{"id":18780,"date":"2021-10-12T11:43:13","date_gmt":"2021-10-12T11:43:13","guid":{"rendered":"https:\/\/easydmarc.com\/blog\/?p=18780"},"modified":"2026-01-26T13:21:59","modified_gmt":"2026-01-26T13:21:59","slug":"how-to-configure-dkim-opendkim-with-postfix","status":"publish","type":"post","link":"https:\/\/easydmarc.com\/blog\/how-to-configure-dkim-opendkim-with-postfix\/","title":{"rendered":"How to Configure DKIM (OpenDKIM) with Postfix"},"content":{"rendered":"\n<p><a href=\"https:\/\/easydmarc.com\/blog\/glossary\/dkim\/\">DomainKeys Identified Mail (DKIM)<\/a> is an email authentication method that protects email senders and recipients from spam, spoofing, and phishing. It uses &#8220;public key cryptography&#8221; to verify that an email message was sent from an authorized mail server for a particular domain and hasn&#8217;t been tampered with during transit. OpenDKIM is an open-source implementation of the DKIM sender authentication system. It integrates into Postfix or Sendmail, the two most common Mail Transfer Agents (MTAs).&nbsp;<\/p>\n\n\n\n<p>Configuring OpenDKIM with Postfix can seem daunting, particularly for those unfamiliar with the process. However, with the right approach, you can accomplish it relatively quickly. This guide will walk you through the process.<\/p>\n\n\n\t\t<div data-elementor-type=\"section\" data-elementor-id=\"50906\" class=\"elementor elementor-50906\" data-elementor-post-type=\"elementor_library\">\n\t\t\t\t\t<section class=\"has_eae_slider elementor-section elementor-top-section elementor-element elementor-element-721164f elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-eae-slider=\"88462\" data-id=\"721164f\" data-element_type=\"section\" data-e-type=\"section\" data-settings=\"{&quot;background_background&quot;:&quot;gradient&quot;}\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"has_eae_slider elementor-column elementor-col-100 elementor-top-column elementor-element elementor-element-0c708e4\" data-eae-slider=\"92482\" data-id=\"0c708e4\" data-element_type=\"column\" data-e-type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<section class=\"has_eae_slider elementor-section elementor-inner-section elementor-element elementor-element-4bf31b5 domain_scanner_top elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-eae-slider=\"33732\" data-id=\"4bf31b5\" data-element_type=\"section\" data-e-type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"has_eae_slider elementor-column elementor-col-100 elementor-inner-column elementor-element elementor-element-0fcd67c\" data-eae-slider=\"73486\" data-id=\"0fcd67c\" data-element_type=\"column\" data-e-type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-5f17691 elementor-widget elementor-widget-heading\" data-id=\"5f17691\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">Get Your Full Domain Health Report\nSee detailed<\/div>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-13b7ef6 elementor-widget elementor-widget-heading\" data-id=\"13b7ef6\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">Enter your email to access the analysis<\/div>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-20f1233 elementor-widget__width-initial domain_scanner elementor-button-align-stretch elementor-widget elementor-widget-form\" data-id=\"20f1233\" data-element_type=\"widget\" data-e-type=\"widget\" data-settings=\"{&quot;button_width&quot;:&quot;30&quot;,&quot;step_next_label&quot;:&quot;Next&quot;,&quot;step_previous_label&quot;:&quot;Previous&quot;,&quot;step_type&quot;:&quot;number_text&quot;,&quot;step_icon_shape&quot;:&quot;circle&quot;}\" data-widget_type=\"form.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<form class=\"elementor-form\" method=\"post\" name=\"Domain-scanner\" aria-label=\"Domain-scanner\">\n\t\t\t<input type=\"hidden\" name=\"post_id\" value=\"50906\"\/>\n\t\t\t<input type=\"hidden\" name=\"form_id\" value=\"20f1233\"\/>\n\t\t\t<input type=\"hidden\" name=\"referer_title\" value=\"EasyDMARC\" \/>\n\n\t\t\t\n\t\t\t<div class=\"elementor-form-fields-wrapper elementor-labels-\">\n\t\t\t\t\t\t\t\t<div class=\"elementor-field-type-recaptcha_v3 elementor-field-group elementor-column elementor-field-group-field_484163c elementor-col-100 recaptcha_v3-bottomright\">\n\t\t\t\t\t<div class=\"elementor-field\" id=\"form-field-field_484163c\"><div class=\"elementor-g-recaptcha\" data-sitekey=\"6LfoqSQoAAAAAERWxCfAJ0wo33fuVHJXWiuw81C3\" data-type=\"v3\" data-action=\"Form\" data-badge=\"bottomright\" data-size=\"invisible\"><\/div><\/div>\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<div class=\"elementor-field-type-hidden elementor-field-group elementor-column elementor-field-group-field_5596341 elementor-col-100\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t<input size=\"1\" type=\"hidden\" name=\"form_fields[field_5596341]\" id=\"form-field-field_5596341\" class=\"elementor-field elementor-size-sm  elementor-field-textual\" value=\"How to Configure DKIM (OpenDKIM) with Postfix\"\/>\n\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<div class=\"elementor-field-type-email elementor-field-group elementor-column elementor-field-group-email elementor-col-70 elementor-field-required\">\n\t\t\t\t\t\t\t\t\t\t\t\t<label for=\"form-field-email\" class=\"elementor-field-label elementor-screen-only\">\n\t\t\t\t\t\t\t\tEmail\t\t\t\t\t\t\t<\/label>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t<input size=\"1\" type=\"email\" name=\"form_fields[email]\" id=\"form-field-email\" class=\"elementor-field elementor-size-sm  elementor-field-textual\" placeholder=\"example@mycompany.com\" required=\"required\"\/>\n\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t<div class=\"elementor-field-group elementor-column elementor-field-type-submit elementor-col-30 e-form__buttons\">\n\t\t\t\t\t<button class=\"elementor-button elementor-size-sm\" type=\"submit\">\n\t\t\t\t\t\t<span class=\"elementor-button-content-wrapper\">\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<span class=\"elementor-button-text\">Send<\/span>\n\t\t\t\t\t\t\t\t\t\t\t\t\t<\/span>\n\t\t\t\t\t<\/button>\n\t\t\t\t<\/div>\n\t\t\t<\/div>\n\t\t<\/form>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<section class=\"has_eae_slider elementor-section elementor-inner-section elementor-element elementor-element-f21a786 thankscon elementor-section-boxed elementor-section-height-default elementor-section-height-default\" data-eae-slider=\"64293\" data-id=\"f21a786\" data-element_type=\"section\" data-e-type=\"section\">\n\t\t\t\t\t\t<div class=\"elementor-container elementor-column-gap-default\">\n\t\t\t\t\t<div class=\"has_eae_slider elementor-column elementor-col-100 elementor-inner-column elementor-element elementor-element-26ae9b5\" data-eae-slider=\"93047\" data-id=\"26ae9b5\" data-element_type=\"column\" data-e-type=\"column\">\n\t\t\t<div class=\"elementor-widget-wrap elementor-element-populated\">\n\t\t\t\t\t\t<div class=\"elementor-element elementor-element-ac64f8a elementor-view-default elementor-widget elementor-widget-icon\" data-id=\"ac64f8a\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"icon.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t<div class=\"elementor-icon-wrapper\">\n\t\t\t<div class=\"elementor-icon\">\n\t\t\t<svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"57\" height=\"57\" viewBox=\"0 0 57 57\" fill=\"none\"><circle cx=\"28.5\" cy=\"28.5\" r=\"26.25\" stroke=\"#0DC3A7\" stroke-width=\"4.5\"><\/circle><path d=\"M12.6665 26.1243L22.1665 37.9993L41.1665 18.9993\" stroke=\"#0DC3A7\" stroke-width=\"4.5\" stroke-linecap=\"round\"><\/path><\/svg>\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-9733c80 elementor-widget elementor-widget-heading\" data-id=\"9733c80\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"heading.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t<div class=\"elementor-heading-title elementor-size-default\">Your report has been successfully sent<\/div>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t<div class=\"elementor-element elementor-element-e450125 elementor-widget elementor-widget-text-editor\" data-id=\"e450125\" data-element_type=\"widget\" data-e-type=\"widget\" data-widget_type=\"text-editor.default\">\n\t\t\t\t<div class=\"elementor-widget-container\">\n\t\t\t\t\t\t\t\t\t<p>Thank you for your submission.<br \/><br \/>Your report has been successfully sent<br \/>to <strong><span id=\"custom-name\">name<\/span><\/strong> email.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t\t<\/div>\n\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t<\/section>\n\t\t\t\t<\/div>\n\t\t\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Why Is DKIM Important for Postfix Servers?<\/strong><\/h2>\n\n\n\n<p>While navigating the intricate world of email servers, you may have stumbled upon DomainKeys Identified Mail (DKIM). But why is it so crucial, particularly for Postfix servers?<\/p>\n\n\n\n<p>DKIM provides a method of validating a domain name identity associated with a message through cryptographic authentication. This process aids in combating <a href=\"https:\/\/easydmarc.com\/blog\/what-is-spoofing-definition-and-explanation\/\">email spoofing<\/a>, thereby enhancing email security. In the context of Postfix servers, integrating DKIM has several distinctive benefits:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Improved Email Deliverability:<\/strong> Improved Email Deliverability: Emails signed with DKIM are less likely to be flagged as spam, ensuring your messages reach the intended recipients. You can confirm inbox placement accuracy by running an <a href=\"https:\/\/easydmarc.com\/tools\/email-deliverability-test\">email deliverability test<\/a> after configuration.<\/li>\n\n\n\n<li><strong>Enhanced Sender Reputation:<\/strong> It boosts your domain&#8217;s credibility and reputation by demonstrating that your emails are legitimate and tamper-proof.<\/li>\n\n\n\n<li><strong>Increased Trust:<\/strong> It verifies the sender&#8217;s identity, reassuring recipients that the emails they receive are authentic.<\/li>\n<\/ul>\n\n\n\n<p>Implementing DKIM in conjunction with Postfix helps increase the reliability and integrity of your email communications, contributing to a safer, more secure digital environment.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Understanding the Basics of OpenDKIM<\/strong><\/h2>\n\n\n\n<p>There are three main components in the OpenDKIM configuration:&nbsp;<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Signing<\/strong>: Adding a private key signature to outgoing emails.<\/li>\n\n\n\n<li><strong>Verifying<\/strong>: On the receiving end, the public key \u2013 located in the sender&#8217;s DNS records \u2013 is used to verify the email signature authenticity.<\/li>\n\n\n\n<li><strong>Key generation<\/strong>: Generating the private and public keys used in signing and verifying.<\/li>\n<\/ol>\n\n\n\n<div class=\"wp-block-group alignfull has-background\" style=\"background-color:#16276c\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<p class=\"has-text-align-center has-white-color has-text-color\" style=\"font-size:20px;line-height:.9\">Quit Tinkering With Technical Configurations Manually<\/p>\n\n\n\n<h2 class=\"wp-block-heading alignwide has-text-align-center has-white-color has-text-color\" id=\"schedule-a-visit\" style=\"font-size:45px;line-height:1.15\">EasyDMARC\u2019s Cloud-Native Platform Makes DKIM Easy!<\/h2>\n\n\n\n<div class=\"wp-block-buttons has-custom-font-size is-horizontal is-content-justification-center is-layout-flex wp-container-core-buttons-is-layout-499968f5 wp-block-buttons-is-layout-flex\" style=\"font-size:14px\">\n<div class=\"wp-block-button has-custom-width wp-block-button__width-50\"><a class=\"wp-block-button__link has-text-color has-background wp-element-button\" href=\"https:\/\/easydmarc.com\/contact-us\" style=\"border-radius:7px;color:#ffffff;background-color:#35c0ff\" target=\"_blank\" rel=\"noreferrer noopener\">Let&#8217;s talk<\/a><\/div>\n<\/div>\n<\/div><\/div>\n\n\n\n<p>It&#8217;s also essential to understand the main factors that contribute to the overall effectiveness of the OpenDKIM setup:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Domain reputation<\/li>\n\n\n\n<li>Consistent configuration<\/li>\n\n\n\n<li>The quality of email content<\/li>\n<\/ul>\n\n\n\n<p>Let&#8217;s look closer at configuring OpenDKIM with Postfix, one of the most popular mail transfer agents.&nbsp;<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Checking the Prerequisites for Installing OpenDKIM<\/strong><\/h2>\n\n\n\n<p>To ensure a smooth and successful configuration of DKIM with Postfix, it is paramount to first address the following prerequisites:<\/p>\n\n\n\n<ol class=\"wp-block-list\">\n<li><strong>Administrative Access:<\/strong> You should have superuser (root) access or an account with <em>sudo<\/em> privilege on your mail server. This is crucial for installing packages and making necessary configuration changes.<\/li>\n\n\n\n<li><strong>Installed Postfix:<\/strong> Postfix must already be installed and properly configured on your server.<\/li>\n\n\n\n<li><strong>Domain Name:<\/strong> A fully qualified domain name (FQDN) is required.<\/li>\n\n\n\n<li><strong>OpenDKIM Package:<\/strong> The OpenDKIM package must be installed on your server.<\/li>\n<\/ol>\n\n\n\n<p>Once you fulfill these prerequisites, you can start configuring DKIM with Postfix.&nbsp;<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>5 Steps to Full OpenDKIM Configuration With Postfix<\/strong><\/h2>\n\n\n\n<p>DKIM is a vital authentication method used to verify the DNS domain of an email sender and the message integrity. Every server administrator and website owner must set up DKIM to protect their server from <a href=\"https:\/\/easydmarc.com\/blog\/phishing-attacks-recognize-and-avoid-email-phishing\/\">phishing scams<\/a> and to improve email deliverability. OpenDKIM configuration with Postfix can seem complex, but it&#8217;s easy if you follow the proper steps.<\/p>\n\n\n\n<p>This section provides a comprehensive, step-by-step guide to configure OpenDKIM with Postfix effectively.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Step 1. Installing OpenDKIM on Your Postfix Server<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li><span style=\"font-weight: 400;\">Start with installation:<\/span><\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>sudo yum install opendkim <\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Step 2: Configure OpenDKIM<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Edit OpenDKIM main configuration file<\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>sudo nano \/etc\/opendkim.conf<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Find the \u201cMode v\u201d line, and change it to \u201cMode sv\u201d. By default, OpenDKIM is set to verification mode (v), which verifies the DKIM signatures of receiving email messages. Changing the mode to &#8220;sv,&#8221; will let us activate the signing mode for outgoing emails.<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-image\"><img fetchpriority=\"high\" decoding=\"async\" width=\"698\" height=\"174\" src=\"https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/1.png\" alt=\"Change \u201cMode v\u201d to \u201cMode sv\u201d\" class=\"wp-image-18786\" srcset=\"https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/1.png 698w, https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/1-300x75.png 300w\" sizes=\"(max-width: 698px) 100vw, 698px\" \/><\/figure>\n\n\n\n<ul class=\"wp-block-list\">\n<li>In the same OpenDKIM Configuration file, find the following lines and remove the Comment (#)<\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-preformatted\"><span style=\"font-weight: 400;\"><code>KeyFile\nKeyTable\nSigningTable\nExternalIgnoreList\nInternalHosts<\/code><\/span><\/pre>\n\n\n\n<figure class=\"wp-block-image\"><img decoding=\"async\" width=\"708\" height=\"335\" src=\"https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/2.png\" alt=\"Remove the Comment (#) for\" class=\"wp-image-18787\" srcset=\"https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/2.png 708w, https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/2-300x142.png 300w\" sizes=\"(max-width: 708px) 100vw, 708px\" \/><\/figure>\n\n\n\n<ul class=\"wp-block-list\">\n<li><span style=\"font-weight: 400;\">At the end of this file, add the following commands on separate lines:<\/span><\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-preformatted\"><span style=\"font-weight: 400;\"><\/span>Domain <span data-darkreader-inline-color=\"\" style=\"color: #ff6600;\">yourdomain.com<\/span><\/pre>\n\n\n\n<pre class=\"wp-block-preformatted\">RequireSafeKeys True<\/pre>\n\n\n\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" width=\"1024\" height=\"267\" src=\"https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/Screenshot-2026-01-26-at-16.44.37-1024x267.png\" alt=\"\" class=\"wp-image-57888\" srcset=\"https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/Screenshot-2026-01-26-at-16.44.37-1024x267.png 1024w, https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/Screenshot-2026-01-26-at-16.44.37-300x78.png 300w, https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/Screenshot-2026-01-26-at-16.44.37-768x200.png 768w, https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/Screenshot-2026-01-26-at-16.44.37-1200x313.png 1200w, https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/Screenshot-2026-01-26-at-16.44.37.png 1318w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p>Because we set RequireSafeKeys to True, OpenDKIM will refuse to sign emails if your private key is &#8220;world-readable&#8221; or owned by the wrong user. You must run these commands on your server to satisfy the security check:<br \/><br \/>1. Set the Owner: The opendkim service user must own the key file.<br \/><br \/><mark style=\"background-color:rgba(0, 0, 0, 0);color:#33982d\" class=\"has-inline-color\">sudo chown opendkim:opendkim \/etc\/opendkim\/keys\/default.privat<\/mark>e<br \/><br \/>2. Restrict Permissions: Set the key to 600 so that only the opendkim user can read it.<br \/><br \/><mark style=\"background-color:rgba(0, 0, 0, 0);color:#33982d\" class=\"has-inline-color\">sudo chmod 600 \/etc\/opendkim\/keys\/default.private<\/mark><br \/><br \/>3. Restart the Service: Apply the changes by restarting OpenDKIM.<br \/><br \/><mark style=\"background-color:rgba(0, 0, 0, 0);color:#33982d\" class=\"has-inline-color\">sudo systemctl restart opendkim<\/mark><\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><span style=\"font-weight: 400;\">Edit the signing table file:<\/span><\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>sudo nano \/etc\/opendkim\/SigningTable<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li><span style=\"font-weight: 400;\">Add the following line at the end of this file<\/span>:<\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>*@<span style=\"color: #ff6600;\" data-darkreader-inline-color=\"\">yourdomain.com<\/span> <span style=\"color: #ff0000;\" data-darkreader-inline-color=\"\">yourselector<\/span>._domainkey.<span style=\"color: #ff6600;\" data-darkreader-inline-color=\"\">yourdomain.com<\/span><\/code><\/pre>\n\n\n\n<p>This tells OpenDKIM that if a sender on your server is using any @yourdomain.com address (in this example, *@easydmarc.me), then it should be signed with the key identified by default._domainkey.yourdomain.com (in this example, default._domainkey.easydmarc.me)<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"742\" height=\"191\" src=\"https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/4.png\" alt=\"sudo nano \/etc\/opendkim\/SigningTable\" class=\"wp-image-18791\" srcset=\"https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/4.png 742w, https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/4-300x77.png 300w\" sizes=\"(max-width: 742px) 100vw, 742px\" \/><\/figure>\n\n\n\n<p>Note: \u201cdefault\u201d is the <a href=\"https:\/\/easydmarc.com\/blog\/what-is-a-dkim-selector-and-how-does-it-work\/\">DKIM selector<\/a>. A domain might have multiple DKIM Signatures. The DKIM selector allows you to choose a particular DKIM Key. You can use any name of your choice, but make sure you don\u2019t have a DKIM Signature already implemented with the same selector name.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Save and close the OpenDKIM main configuration file<\/li>\n\n\n\n<li>Edit the <em>KeyTable<\/em> file<\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>sudo nano \/etc\/opendkim\/KeyTable<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Add the following line:<\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-preformatted\"><span data-darkreader-inline-color=\"\" style=\"color: #ff0000;\">yourselector<\/span>._domainkey.<span data-darkreader-inline-color=\"\" style=\"color: #ff6600;\">yourdomain.com yourdomain.com<\/span>:<span data-darkreader-inline-color=\"\" style=\"color: #ff0000;\">yourselector<\/span>:\/etc\/opendkim\/keys\/<span data-darkreader-inline-color=\"\" style=\"color: #ff6600;\">yourdomain.com<\/span>\/default.private<\/pre>\n\n\n\n<p>This line specifies the location of the DKIM private key. In this screenshot, the selector is the &#8220;default&#8221;.<\/p>\n\n\n\n<p><span style=\"font-weight: 400;\">In this screenshot<\/span><i><span style=\"font-weight: 400;\">, <\/span><\/i><span style=\"font-weight: 400;\">selector<\/span> <span style=\"font-weight: 400;\">is defined as<\/span><i><span style=\"font-weight: 400;\"> default<\/span><\/i><\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"832\" height=\"137\" src=\"https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/5.png\" alt=\"sudo nano \/etc\/opendkim\/KeyTable\" class=\"wp-image-18792\" srcset=\"https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/5.png 832w, https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/5-300x49.png 300w, https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/5-768x126.png 768w\" sizes=\"(max-width: 832px) 100vw, 832px\" \/><\/figure>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Save and close the file<\/li>\n\n\n\n<li>Edit the OpenDKIM Trusted Hosts file<\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>sudo nano \/etc\/opendkim\/TrustedHosts<\/code><\/pre>\n\n\n\n<p><b><br \/><\/b><span style=\"font-weight: 400;\"><i>127.0.0.0.1<\/i> and <i>::1<\/i> are included in this file by default.<\/span><\/p>\n\n\n\n<p>Add the following line<\/p>\n\n\n\n<pre class=\"wp-block-code\"><code><span style=\"font-weight: 400;\"><span data-darkreader-inline-color=\"\" style=\"color: #ff6600;\"><b>*.yourdomain.com<\/b><\/span><\/span><\/code><\/pre>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"661\" height=\"176\" src=\"https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/6.png\" alt=\"sudo nano \/etc\/opendkim\/TrustedHosts\" class=\"wp-image-18795\" srcset=\"https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/6.png 661w, https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/6-300x80.png 300w\" sizes=\"(max-width: 661px) 100vw, 661px\" \/><\/figure>\n\n\n\n<div class=\"wp-block-buttons is-content-justification-center is-layout-flex wp-container-core-buttons-is-layout-16018d1d wp-block-buttons-is-layout-flex\">\n<div class=\"wp-block-button\"><a class=\"wp-block-button__link has-background-color has-text-color has-background has-link-color wp-element-button\" style=\"background-color:#3fbdf7\">Start free trial<\/a><\/div>\n<\/div>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Step 3: Generate Private\/Public Keys<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Create a new directory for your domain<\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code><\/code><code>sudo mkdir \/etc\/opendkim\/keys\/<span style=\"color: #ff6600;\" data-darkreader-inline-color=\"\">yourdomain.com<\/span><\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li><span style=\"font-weight: 400;\">Generate keys using opendkim-genkey tool<\/span><\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>sudo opendkim-genkey -b 1024 -d <span style=\"color: #ff6600;\" data-darkreader-inline-color=\"\">yourdomain.com<\/span> -D \/etc\/opendkim\/keys\/<span style=\"color: #ff6600;\" data-darkreader-inline-color=\"\">yourdomain.com<\/span> -s <span style=\"color: #ff0000;\" data-darkreader-inline-color=\"\">yourselector<\/span> -v<\/code><\/pre>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"933\" height=\"44\" src=\"https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/7.png\" alt=\"sudo opendkim-genkey -b 1024 -d domain.com -D \/etc\/opendkim\/keys\/domain.com -s selector -v\" class=\"wp-image-18796\" srcset=\"https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/7.png 933w, https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/7-300x14.png 300w, https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/7-768x36.png 768w\" sizes=\"(max-width: 933px) 100vw, 933px\" \/><\/figure>\n\n\n\n<ul class=\"wp-block-list\">\n<li><span style=\"font-weight: 400;\">Make opendkim the key owner<\/span><\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-preformatted\"><code>sudo chown opendkim:opendkim \/etc\/opendkim\/keys -R<\/code><b> <\/b><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Step 4: Publish the created public key in your DNS<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Get and display the Public Key<\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>sudo cat \/etc\/opendkim\/keys\/<span style=\"color: #ff6600;\" data-darkreader-inline-color=\"\">yourdomain.com<\/span>\/default.txt<\/code><\/pre>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"962\" height=\"123\" src=\"https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/8.png\" alt=\"sudo cat \/etc\/opendkim\/keys\/domain.com\/default.txt\" class=\"wp-image-18799\" srcset=\"https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/8.png 962w, https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/8-300x38.png 300w, https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/8-768x98.png 768w\" sizes=\"(max-width: 962px) 100vw, 962px\" \/><\/figure>\n\n\n\n<ul class=\"wp-block-list\">\n<li><span style=\"font-weight: 400;\">Implement it in your DNS (In this example, Cloudflare)<\/span>.<\/li>\n<\/ul>\n\n\n\n<p><span style=\"font-weight: 400;\">Important Notes:<br \/>Name\/Target: <span data-darkreader-inline-color=\"\" style=\"color: #ff0000;\">yourselector<\/span>._domainkey<br \/>Content: Value you\u2019ve copied in the previous stage. <\/span><b>Make sure to remove any spaces or double-quotes.<\/b><\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"287\" src=\"https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/9.png\" alt=\"Implement the Public Key in your DNS\" class=\"wp-image-18800\" srcset=\"https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/9.png 1024w, https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/9-300x84.png 300w, https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/9-768x215.png 768w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<ul class=\"wp-block-list\">\n<li>After publishing <a href=\"https:\/\/easydmarc.com\/blog\/dkim-record-how-to-create-add-and-check-dkim-records\/\">DKIM Public key<\/a> in your DNS, confirm DKIM is valid using <a href=\"https:\/\/easydmarc.com\/tools\/dkim-lookup\">EasyDMARC DKIM Lookup<\/a> tool.<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"843\" height=\"498\" src=\"https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/10.png\" alt=\"easydmarc dkim lookup tool\" class=\"wp-image-18802\" srcset=\"https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/10.png 843w, https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/10-300x177.png 300w, https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/10-768x454.png 768w\" sizes=\"(max-width: 843px) 100vw, 843px\" \/><\/figure>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Step 5: Connect Postfix to OpenDKIM<\/strong><\/h3>\n\n\n\n<p>Now that you&#8217;ve configured OpenDKIM, it&#8217;s time to implement Postfix DKIM. Let&#8217;s follow the Postfix OpenDKIM configuration process.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Edit Postfix main configuration file<\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>sudo nano \/etc\/postfix\/main.cf<\/code><\/pre>\n\n\n\n<ul class=\"wp-block-list\">\n<li><span style=\"font-weight: 400;\">Add the following lines at the end of the \u201cmain.cf\u201d file<\/span><\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-preformatted\"><code>smtpd_milters = inet:127.0.0.1:8891\nnon_smtpd_milters = $smtpd_milters<\/code> \n<code>milter_default_action = accept <\/code><\/pre>\n\n\n\n<p>This will let Postfix call OpenDKIM via the milter protocol.<\/p>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"327\" height=\"211\" src=\"https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/11.png\" alt=\"open dkim configuration\" class=\"wp-image-18805\" srcset=\"https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/11.png 327w, https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/11-300x194.png 300w\" sizes=\"(max-width: 327px) 100vw, 327px\" \/><\/figure>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Save and close the file.<\/li>\n\n\n\n<li>Restart OpenDKIM and Postfix<\/li>\n<\/ul>\n\n\n\n<pre class=\"wp-block-code\"><code>sudo service opendkim restart<\/code><\/pre>\n\n\n\n<pre class=\"wp-block-code\"><code>sudo service postfix restart<\/code><\/pre>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Step 6: Test Your DKIM Configuration<\/strong><\/h3>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Send a test email from your server to confirm that Postfix DKIM is working.<\/li>\n<\/ul>\n\n\n\n<figure class=\"wp-block-image\"><img loading=\"lazy\" decoding=\"async\" width=\"511\" height=\"234\" src=\"https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/12.png\" alt=\"Send a Test email and confirm DKIM is working\" class=\"wp-image-18813\" srcset=\"https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/12.png 511w, https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/12-300x137.png 300w\" sizes=\"(max-width: 511px) 100vw, 511px\" \/><\/figure>\n\n\n\n<p>Now, you&#8217;ve configured OpenDKIM on Postfix.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Troubleshooting DKIM With OpenDKIM and Postfix<\/strong><\/h2>\n\n\n\n<figure class=\"wp-block-table\"><table><tbody><tr><td>Issue<\/td><td>Solution<\/td><\/tr><tr><td><strong>Incorrect DNS records<\/strong><br \/>DKIM relies on DNS records to verify the authenticity of emails, so the verification process will fail if the records are incorrect or missing.<\/td><td>Double-check the DNS records and ensure their correct configuration. You can use EasyDMARC&#8217;s <a href=\"https:\/\/easydmarc.com\/tools\/domain-scanner\">domain health checker<\/a> to find and solve DNS issues.<\/td><\/tr><tr><td><strong>Incorrect OpenDKIM configuration<\/strong><br \/>This can happen if the configuration file contains errors or if the settings are not properly configured.<\/td><td>Check the configuration file and make sure all settings are correct. You can also use the opendkim-testkey command to test the configuration and verify that it is working properly.<\/td><\/tr><tr><td><strong>Postfix configuration errors<\/strong><br \/>Postfix misconfigurations may lead to email signature verification failures.<\/td><td>Check the Postfix configuration file and make sure all settings are correct. You can also use the Postfix mailq command to check the mail queue to find issues with sending or receiving emails.<\/td><\/tr><tr><td><strong>Issues with firewalls or network settings<\/strong><br \/>If the firewall is blocking DKIM traffic or the network settings contain misconfigurations, DKIM may not work as expected.<\/td><td>Check the firewall settings and make sure DKIM traffic is allowed. You can also check the network settings and ensure they are correct.<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Best Practices for Implementing DKIM With OpenDKIM and Postfix<\/strong><\/h2>\n\n\n\n<p>Understanding the best practices for implementing DKIM with OpenDKIM and Postfix is crucial for ensuring secure and efficient email delivery. Here, we delve into the top strategies to help streamline this process.&nbsp;<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Choose a Strong Selector:<\/strong><\/li>\n<\/ul>\n\n\n\n<p>Selectors are integral to DKIM implementation. Choosing a robust and unique selector reduces the chances of email spoofing and improves email deliverability.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Generate Secure Keys:<\/strong><\/li>\n<\/ul>\n\n\n\n<p>Employ RSA keys with a minimum length of 2048 bits for DKIM signatures. This increases the security of your emails and mitigates risks associated with key compromises.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Regularly Rotate Keys:<\/strong><\/li>\n<\/ul>\n\n\n\n<p>Regularly rotating your DKIM keys is a good security practice. It limits the amount of time malicious actors can use a compromised key.<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Monitor Email Delivery:<\/strong><\/li>\n<\/ul>\n\n\n\n<p>Monitor your email delivery rates and bounce rates closely. This helps you identify potential issues with your DKIM configuration and rectify them before they impact your email deliverability.<br \/><\/p>\n\n\n\n<p>Note: Implementing DKIM is a technical process that requires a solid understanding of email servers and security protocols. We recommend you consult with an IT professional or conduct thorough research before proceeding.<\/p>\n\n\n\n<div class=\"wp-block-group alignfull has-background\" style=\"background-color:#16276c\"><div class=\"wp-block-group__inner-container is-layout-constrained wp-block-group-is-layout-constrained\">\n<p class=\"has-text-align-center has-white-color has-text-color\" style=\"font-size:20px;line-height:.9\">Get the Most out of Email Authentication Best Practices<\/p>\n\n\n\n<h2 class=\"wp-block-heading alignwide has-text-align-center has-white-color has-text-color\" id=\"schedule-a-visit\" style=\"font-size:45px;line-height:1.15\">Start Your DKIM Journey Now!<\/h2>\n\n\n\n<div class=\"wp-block-buttons has-custom-font-size is-horizontal is-content-justification-center is-layout-flex wp-container-core-buttons-is-layout-499968f5 wp-block-buttons-is-layout-flex\" style=\"font-size:14px\">\n<div class=\"wp-block-button has-custom-width wp-block-button__width-50\"><a class=\"wp-block-button__link has-text-color has-background wp-element-button\" href=\"https:\/\/easydmarc.com\/contact-us\" style=\"border-radius:7px;color:#ffffff;background-color:#35c0ff\" target=\"_blank\" rel=\"noreferrer noopener\">Let&#8217;s talk<\/a><\/div>\n<\/div>\n<\/div><\/div>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Conclusion<\/strong><\/h2>\n\n\n\n<p>Setting up DKIM with OpenDKIM and Postfix might seem intimidating initially, but it follows a systematic approach. This article has taken you through the step-by-step process, clarifying complex concepts and offering technical guidance.&nbsp;<\/p>\n\n\n\n<p>Remember, proper configuration of DKIM is crucial for email security, ensuring that the emails you send are not flagged as spam or malicious.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>DomainKeys Identified Mail (DKIM) is an email authentication &#8230;<\/p>\n","protected":false},"author":25,"featured_media":18925,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":""},"categories":[205,209],"tags":[],"class_list":["post-18780","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-knowledge-base","category-source-configuration"],"acf":[],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v27.4 (Yoast SEO v27.4) - https:\/\/yoast.com\/product\/yoast-seo-premium-wordpress\/ -->\n<title>How to Configure DKIM (OpenDKIM) with Postfix | EasyDMARC<\/title>\n<meta name=\"description\" content=\"This article explains and showcases step by step how to Install and Configure OpenDKIM with Postfix on CentOS Linux\u00a0\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/easydmarc.com\/blog\/how-to-configure-dkim-opendkim-with-postfix\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"How to Configure DKIM (OpenDKIM) with Postfix\" \/>\n<meta property=\"og:description\" content=\"This article explains and showcases step by step how to Install and Configure OpenDKIM with Postfix on CentOS Linux\u00a0\" \/>\n<meta property=\"og:url\" content=\"https:\/\/easydmarc.com\/blog\/how-to-configure-dkim-opendkim-with-postfix\/\" \/>\n<meta property=\"og:site_name\" content=\"EasyDMARC\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/EasyDMARC\/\" \/>\n<meta property=\"article:published_time\" content=\"2021-10-12T11:43:13+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2026-01-26T13:21:59+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/OpenDKIM-Postfix.jpg\" \/>\n\t<meta property=\"og:image:width\" content=\"1440\" \/>\n\t<meta property=\"og:image:height\" content=\"910\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/jpeg\" \/>\n<meta name=\"author\" content=\"Hagop K.\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:creator\" content=\"@easydmarc\" \/>\n<meta name=\"twitter:site\" content=\"@easydmarc\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"Hagop K.\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"10 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/easydmarc.com\\\/blog\\\/how-to-configure-dkim-opendkim-with-postfix\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/easydmarc.com\\\/blog\\\/how-to-configure-dkim-opendkim-with-postfix\\\/\"},\"author\":{\"name\":\"Hagop K.\",\"@id\":\"https:\\\/\\\/easydmarc.com\\\/blog\\\/#\\\/schema\\\/person\\\/740e38b8d7f98e6c4141ae2931ca5a2a\"},\"headline\":\"How to Configure DKIM (OpenDKIM) with Postfix\",\"datePublished\":\"2021-10-12T11:43:13+00:00\",\"dateModified\":\"2026-01-26T13:21:59+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/easydmarc.com\\\/blog\\\/how-to-configure-dkim-opendkim-with-postfix\\\/\"},\"wordCount\":1585,\"publisher\":{\"@id\":\"https:\\\/\\\/easydmarc.com\\\/blog\\\/#organization\"},\"image\":{\"@id\":\"https:\\\/\\\/easydmarc.com\\\/blog\\\/how-to-configure-dkim-opendkim-with-postfix\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/easydmarc.com\\\/blog\\\/wp-content\\\/uploads\\\/2021\\\/10\\\/OpenDKIM-Postfix.jpg\",\"articleSection\":[\"Knowledge Base\",\"Source Configuration\"],\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\\\/\\\/easydmarc.com\\\/blog\\\/how-to-configure-dkim-opendkim-with-postfix\\\/#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/easydmarc.com\\\/blog\\\/how-to-configure-dkim-opendkim-with-postfix\\\/\",\"url\":\"https:\\\/\\\/easydmarc.com\\\/blog\\\/how-to-configure-dkim-opendkim-with-postfix\\\/\",\"name\":\"How to Configure DKIM (OpenDKIM) with Postfix | EasyDMARC\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/easydmarc.com\\\/blog\\\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\\\/\\\/easydmarc.com\\\/blog\\\/how-to-configure-dkim-opendkim-with-postfix\\\/#primaryimage\"},\"image\":{\"@id\":\"https:\\\/\\\/easydmarc.com\\\/blog\\\/how-to-configure-dkim-opendkim-with-postfix\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/easydmarc.com\\\/blog\\\/wp-content\\\/uploads\\\/2021\\\/10\\\/OpenDKIM-Postfix.jpg\",\"datePublished\":\"2021-10-12T11:43:13+00:00\",\"dateModified\":\"2026-01-26T13:21:59+00:00\",\"description\":\"This article explains and showcases step by step how to Install and Configure OpenDKIM with Postfix on CentOS Linux\u00a0\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/easydmarc.com\\\/blog\\\/how-to-configure-dkim-opendkim-with-postfix\\\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/easydmarc.com\\\/blog\\\/how-to-configure-dkim-opendkim-with-postfix\\\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/easydmarc.com\\\/blog\\\/how-to-configure-dkim-opendkim-with-postfix\\\/#primaryimage\",\"url\":\"https:\\\/\\\/easydmarc.com\\\/blog\\\/wp-content\\\/uploads\\\/2021\\\/10\\\/OpenDKIM-Postfix.jpg\",\"contentUrl\":\"https:\\\/\\\/easydmarc.com\\\/blog\\\/wp-content\\\/uploads\\\/2021\\\/10\\\/OpenDKIM-Postfix.jpg\",\"width\":1440,\"height\":910,\"caption\":\"OpenDKIM Postfix\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/easydmarc.com\\\/blog\\\/how-to-configure-dkim-opendkim-with-postfix\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/easydmarc.com\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Knowledge Base\",\"item\":\"https:\\\/\\\/easydmarc.com\\\/blog\\\/category\\\/knowledge-base\\\/\"},{\"@type\":\"ListItem\",\"position\":3,\"name\":\"Source Configuration\",\"item\":\"https:\\\/\\\/easydmarc.com\\\/blog\\\/category\\\/knowledge-base\\\/source-configuration\\\/\"},{\"@type\":\"ListItem\",\"position\":4,\"name\":\"How to Configure DKIM (OpenDKIM) with Postfix\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/easydmarc.com\\\/blog\\\/#website\",\"url\":\"https:\\\/\\\/easydmarc.com\\\/blog\\\/\",\"name\":\"EasyDMARC\",\"description\":\"Blog\",\"publisher\":{\"@id\":\"https:\\\/\\\/easydmarc.com\\\/blog\\\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/easydmarc.com\\\/blog\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/easydmarc.com\\\/#organization\",\"name\":\"EasyDMARC\",\"url\":\"https:\\\/\\\/easydmarc.com\\\/\",\"logo\":{\"@type\":\"ImageObject\",\"url\":\"https:\\\/\\\/easydmarc.com\\\/img\\\/logo.png\"},\"image\":{\"@id\":\"https:\\\/\\\/easydmarc.com\\\/blog\\\/#\\\/schema\\\/logo\\\/image\\\/\"},\"sameAs\":[\"https:\\\/\\\/www.facebook.com\\\/EasyDMARC\\\/\",\"https:\\\/\\\/x.com\\\/easydmarc\",\"https:\\\/\\\/www.linkedin.com\\\/company\\\/easydmarc\\\/mycompany\\\/\"]},{\"@type\":\"Person\",\"@id\":\"https:\\\/\\\/easydmarc.com\\\/blog\\\/#\\\/schema\\\/person\\\/740e38b8d7f98e6c4141ae2931ca5a2a\",\"name\":\"Hagop K.\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/bb6e65e2ae3c6e57f798515a978995b899d1d972034c909397efad978249be85?s=96&r=g\",\"url\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/bb6e65e2ae3c6e57f798515a978995b899d1d972034c909397efad978249be85?s=96&r=g\",\"contentUrl\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/bb6e65e2ae3c6e57f798515a978995b899d1d972034c909397efad978249be85?s=96&r=g\",\"caption\":\"Hagop K.\"},\"sameAs\":[\"https:\\\/\\\/www.linkedin.com\\\/in\\\/hagopkhatchoian\\\/\"],\"url\":\"https:\\\/\\\/easydmarc.com\\\/blog\\\/author\\\/hagop-khatchoian\\\/\"}]}<\/script>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"How to Configure DKIM (OpenDKIM) with Postfix | EasyDMARC","description":"This article explains and showcases step by step how to Install and Configure OpenDKIM with Postfix on CentOS Linux\u00a0","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/easydmarc.com\/blog\/how-to-configure-dkim-opendkim-with-postfix\/","og_locale":"en_US","og_type":"article","og_title":"How to Configure DKIM (OpenDKIM) with Postfix","og_description":"This article explains and showcases step by step how to Install and Configure OpenDKIM with Postfix on CentOS Linux\u00a0","og_url":"https:\/\/easydmarc.com\/blog\/how-to-configure-dkim-opendkim-with-postfix\/","og_site_name":"EasyDMARC","article_publisher":"https:\/\/www.facebook.com\/EasyDMARC\/","article_published_time":"2021-10-12T11:43:13+00:00","article_modified_time":"2026-01-26T13:21:59+00:00","og_image":[{"width":1440,"height":910,"url":"https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/OpenDKIM-Postfix.jpg","type":"image\/jpeg"}],"author":"Hagop K.","twitter_card":"summary_large_image","twitter_creator":"@easydmarc","twitter_site":"@easydmarc","twitter_misc":{"Written by":"Hagop K.","Est. reading time":"10 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/easydmarc.com\/blog\/how-to-configure-dkim-opendkim-with-postfix\/#article","isPartOf":{"@id":"https:\/\/easydmarc.com\/blog\/how-to-configure-dkim-opendkim-with-postfix\/"},"author":{"name":"Hagop K.","@id":"https:\/\/easydmarc.com\/blog\/#\/schema\/person\/740e38b8d7f98e6c4141ae2931ca5a2a"},"headline":"How to Configure DKIM (OpenDKIM) with Postfix","datePublished":"2021-10-12T11:43:13+00:00","dateModified":"2026-01-26T13:21:59+00:00","mainEntityOfPage":{"@id":"https:\/\/easydmarc.com\/blog\/how-to-configure-dkim-opendkim-with-postfix\/"},"wordCount":1585,"publisher":{"@id":"https:\/\/easydmarc.com\/blog\/#organization"},"image":{"@id":"https:\/\/easydmarc.com\/blog\/how-to-configure-dkim-opendkim-with-postfix\/#primaryimage"},"thumbnailUrl":"https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/OpenDKIM-Postfix.jpg","articleSection":["Knowledge Base","Source Configuration"],"inLanguage":"en-US","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/easydmarc.com\/blog\/how-to-configure-dkim-opendkim-with-postfix\/#respond"]}]},{"@type":"WebPage","@id":"https:\/\/easydmarc.com\/blog\/how-to-configure-dkim-opendkim-with-postfix\/","url":"https:\/\/easydmarc.com\/blog\/how-to-configure-dkim-opendkim-with-postfix\/","name":"How to Configure DKIM (OpenDKIM) with Postfix | EasyDMARC","isPartOf":{"@id":"https:\/\/easydmarc.com\/blog\/#website"},"primaryImageOfPage":{"@id":"https:\/\/easydmarc.com\/blog\/how-to-configure-dkim-opendkim-with-postfix\/#primaryimage"},"image":{"@id":"https:\/\/easydmarc.com\/blog\/how-to-configure-dkim-opendkim-with-postfix\/#primaryimage"},"thumbnailUrl":"https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/OpenDKIM-Postfix.jpg","datePublished":"2021-10-12T11:43:13+00:00","dateModified":"2026-01-26T13:21:59+00:00","description":"This article explains and showcases step by step how to Install and Configure OpenDKIM with Postfix on CentOS Linux\u00a0","breadcrumb":{"@id":"https:\/\/easydmarc.com\/blog\/how-to-configure-dkim-opendkim-with-postfix\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/easydmarc.com\/blog\/how-to-configure-dkim-opendkim-with-postfix\/"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/easydmarc.com\/blog\/how-to-configure-dkim-opendkim-with-postfix\/#primaryimage","url":"https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/OpenDKIM-Postfix.jpg","contentUrl":"https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/OpenDKIM-Postfix.jpg","width":1440,"height":910,"caption":"OpenDKIM Postfix"},{"@type":"BreadcrumbList","@id":"https:\/\/easydmarc.com\/blog\/how-to-configure-dkim-opendkim-with-postfix\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/easydmarc.com\/"},{"@type":"ListItem","position":2,"name":"Knowledge Base","item":"https:\/\/easydmarc.com\/blog\/category\/knowledge-base\/"},{"@type":"ListItem","position":3,"name":"Source Configuration","item":"https:\/\/easydmarc.com\/blog\/category\/knowledge-base\/source-configuration\/"},{"@type":"ListItem","position":4,"name":"How to Configure DKIM (OpenDKIM) with Postfix"}]},{"@type":"WebSite","@id":"https:\/\/easydmarc.com\/blog\/#website","url":"https:\/\/easydmarc.com\/blog\/","name":"EasyDMARC","description":"Blog","publisher":{"@id":"https:\/\/easydmarc.com\/blog\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/easydmarc.com\/blog\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/easydmarc.com\/#organization","name":"EasyDMARC","url":"https:\/\/easydmarc.com\/","logo":{"@type":"ImageObject","url":"https:\/\/easydmarc.com\/img\/logo.png"},"image":{"@id":"https:\/\/easydmarc.com\/blog\/#\/schema\/logo\/image\/"},"sameAs":["https:\/\/www.facebook.com\/EasyDMARC\/","https:\/\/x.com\/easydmarc","https:\/\/www.linkedin.com\/company\/easydmarc\/mycompany\/"]},{"@type":"Person","@id":"https:\/\/easydmarc.com\/blog\/#\/schema\/person\/740e38b8d7f98e6c4141ae2931ca5a2a","name":"Hagop K.","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/secure.gravatar.com\/avatar\/bb6e65e2ae3c6e57f798515a978995b899d1d972034c909397efad978249be85?s=96&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/bb6e65e2ae3c6e57f798515a978995b899d1d972034c909397efad978249be85?s=96&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/bb6e65e2ae3c6e57f798515a978995b899d1d972034c909397efad978249be85?s=96&r=g","caption":"Hagop K."},"sameAs":["https:\/\/www.linkedin.com\/in\/hagopkhatchoian\/"],"url":"https:\/\/easydmarc.com\/blog\/author\/hagop-khatchoian\/"}]}},"jetpack_featured_media_url":"https:\/\/easydmarc.com\/blog\/wp-content\/uploads\/2021\/10\/OpenDKIM-Postfix.jpg","_links":{"self":[{"href":"https:\/\/easydmarc.com\/blog\/wp-json\/wp\/v2\/posts\/18780","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/easydmarc.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/easydmarc.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/easydmarc.com\/blog\/wp-json\/wp\/v2\/users\/25"}],"replies":[{"embeddable":true,"href":"https:\/\/easydmarc.com\/blog\/wp-json\/wp\/v2\/comments?post=18780"}],"version-history":[{"count":11,"href":"https:\/\/easydmarc.com\/blog\/wp-json\/wp\/v2\/posts\/18780\/revisions"}],"predecessor-version":[{"id":57891,"href":"https:\/\/easydmarc.com\/blog\/wp-json\/wp\/v2\/posts\/18780\/revisions\/57891"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/easydmarc.com\/blog\/wp-json\/wp\/v2\/media\/18925"}],"wp:attachment":[{"href":"https:\/\/easydmarc.com\/blog\/wp-json\/wp\/v2\/media?parent=18780"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/easydmarc.com\/blog\/wp-json\/wp\/v2\/categories?post=18780"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/easydmarc.com\/blog\/wp-json\/wp\/v2\/tags?post=18780"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}