SPF Checker

The SPF record protects a company's domain from spoofing while improving its sender reputation with MBPs (Mailbox Providers) such as Google, Microsoft, Verizon, etc. Most companies and individuals use SPF records to prevent spoofing and enhance email security and deliverability.

Another reason for setting up an SPF record is to help prevent your domain from being used by spammers to send out fraudulent emails that appear to come from your domain. Setting an SPF record allows you to specify which IP addresses are allowed to send emails on behalf of your domain, and any emails sent from an IP address not listed in the record will be flagged as suspicious.

EasyDMARC’s SPF Checker lets you verify whether an SPF record exists on a domain’s DNS and whether it’s deployed correctly.
It checks for correct syntax and other issues, such as missing nameservers, invalid or missing IP addresses, and incorrect TXT records.

SPF Lookup verifies the sender's identity when an email is sent out. It involves performing a DNS lookup of the domain the sender claims to be from and verifying that the sender's IP address is listed in the SPF record for that domain. If the IP address does not match, then the email is considered to be from a fraudulent sender.

SPF Lookup is a critical security measure to prevent spoofing and differentiate between legitimate and fraudulent sources.

Read more about the SPF standard here.

EasyDMARC’s SPF Record Checker helps to ensure that:

• The SPF record exists
• The IP addresses of the sources are correct
• No syntax errors exist
• The record doesn’t contain “10 DNS lookup” error

It’s easy; simply use EasyDMARC’s free SPF Record Checker tool. Enter the domain name in the box and click “Check SPF.” You'll then receive all lookup and check results for that domain.

Alternatively, you can check the SPF records manually by running the command “nslookup -type=txt” followed by the domain name in a command prompt.

When an email is sent, the receiving server checks the sender’s return-path address and verifies whether the domain has a valid SPF record. SPF works by creating a special DNS record listing the mail servers authorized to send emails on behalf of that domain. If the sender’s IP address matches the authorized servers in the SPF record, the email is considered authenticated and delivered to the recipient's mailbox. If the IP address is not authorized, the receiving mail server can reject the email or mark it as spam.

SPF is one of the oldest authentication methods, but it is not foolproof. One limitation of SPF is that it only checks the "envelope" sender address, which is used for routing purposes. It doesn't look at the "From" address visible to the recipient. This means that SPF cannot prevent all types of email spoofing.

Moreover, SPF is just one of several email authentication methods, including DomainKeys Identified Mail (DKIM) and Domain-based Message Authentication, Reporting, and Conformance (DMARC). Most mail servers don't solely rely on SPF policy to accept or reject emails. However, some local providers still "respect" the original SPF policy with -all, which means that if an email fails the SPF check, it'll be rejected.

1. Allow only one server to send email:
2. v=spf1 ip4:198.51.100.1 -all
3. This SPF record allows only the mail server with IP address 198.51.100.1 to send emails. All other servers will be considered unauthorized.
4. Allow a list of IP addresses within a given range to send email:
5. v=spf1 ip4:192.0.2.0/24 -all
6. This SPF record allows any server with an IP address within the range of 192.0.2.0/24 to send emails. All other servers will be considered unauthorized.
7. An SPF record that includes a third-party email service:
8. v=spf1 include:_spf.google.com include:spf.protection.outlook.com -all
9. This SPF record allows any servers listed in Google's SPF record (_spf.google.com) and Microsoft's SPF record (spf.protection.outlook.com) to send emails on behalf of the domain. All other servers will be considered unauthorized.
10. SPF record that combines IPv4, IPv6, and third-party services:
11. v=spf1 ip4:192.0.2.0/24 ip6:2001:0db8:85a3::/64 include:_spf.google.com include:spf.protection.outlook.com -all
12. This SPF record allows any server with an IPv4 address within the range 192.0.2.0/24, any server with an IPv6 address within the range 2001:0db8:85a3::/64, as well as any server listed in Google's SPF record (_spf.google.com) and Microsoft's SPF record (spf.protection.outlook.com), to send emails on behalf of the domain. All other servers will be considered unauthorized.

If an SPF diagnostic tool isn't your cup of tea, use the command line to check your SPF record.

1. Open your terminal or command prompt on your computer.
2. Type in dig txt domain.com or nslookup -q=txt domain.com. Replace domain.com with the domain name you want to check.
3. Click "Enter" to execute the command.
4. You will see a list of TXT records associated with the domain.
5. Look for the TXT record that starts with v=spf1. This is the SPF record for the domain.

dig txt easydmarc.us

; <<>> DiG 9.10.6 <<>> txt easydmarc.us

;; global options: +cmd

;; Got answer:

;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 21471

;; flags: qr rd ra; QUERY: 1, ANSWER: 4, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:

;easydmarc.us. IN TXT

;; ANSWER SECTION:

easydmarc.us. 300 IN TXT "v=spf1 include:_spf.easydmarc_us._d.easydmarc.pro ~all"

Sender Policy Framework (SPF) is an essential email authentication protocol for improving email deliverability. By authorizing specific IP addresses to send emails on behalf of a domain, SPF helps to verify the authenticity of incoming messages. When an email has a valid SPF record, it's more likely to be trusted by receiving mail servers, leading to improved deliverability rates.

Additionally, SPF is a critical component in achieving DMARC compliance, essential for maintaining a positive email reputation and enforcing email authentication protocols. By implementing SPF alongside DKIM, organizations can ensure their emails are correctly authenticated and protected from spoofing or phishing attacks, ultimately leading to higher deliverability rates and better overall email performance.

We strongly recommend automation, especially if you’re managing multiple domains in large organizations.

While it is possible to manually manage your SPF record, efficiency and speed are what you get with SPF record management services like Managed SPF by EasyDMARC. You can avoid making syntax errors during SPF configuration and management that would render your record useless. Keeping the record up-to-date is yet another benefit of using a managed solution. We recommend you assess your organization’s needs and circumstances to make the right choice.

10 DNS lookups is one of SPF’s limitations. Each time an email server receives an email, it needs to look up the SPF record for the sender's domain to determine whether the email is legitimate or not. If the checks bypass the limit, SPF fails.

Each additional lookup adds to the email processing time and can increase the risk of email delivery delays or timeouts.

An SPF PermError occurs when the SPF record contains issues that prevent it from being correctly interpreted. This leads to SPF failure and undelivered emails. Common causes include having multiple SPF records for a domain, syntax errors in the record, or exceeding the allowed limit of 10 DNS lookups.

An SPF Validator tool, such as our SPF Checker, can help identify and resolve these issues, ensuring DMARC compliance and improved inbox placement.

Email deliverability improvement is an indirect effect of implementing email authentication protocols (SPF, DKIM, and DMARC). DMARC rests on SPF and DKIM protocol success. If one of them fails, the chance of DMARC success is drastically diminished. SPF PermError causes the SPF protocol to fail, so DMARC compliance, and subsequently, email deliverability, is endangered.

SPF flattening replaces SPF mechanisms that complicate the record with IP4 and IP6 rules, eliminating multiple DNS lookups and creating a more optimized record. Leaving the process with a trusted SPF service also reduces your involvement and automates it.