Top 8 Threats to Email Security for Large Enterprises | EasyDMARC

Top 8 Threats to Email Security for Large Enterprises

9 Min Read

Every year, we experience an increase in email security threats. Phishing, whaling, malware, and other attacks are becoming an issue for many large companies. The cybersecurity industry has to deal with this challenge since email is the primeform of communication in many industries. 

According to a security report issued by Ironscales, nearly 90% of all cyberattacks are carried out by email. Software protection isn’t enough. Your company also requires the best practices for business email security and comprehensive training. A multi-layered security plan can mitigate email security risks, but a deep understanding of these threats works much better in the long run.

In the following blog, we discuss some of the most recurrent email threats in cyber security. We’ll also talk about some of the steps you can take to protect your enterprise.

Outsider Threats

We call outsider email security threats any risk posed by external attempts to infiltrate your network without authorization, with the goal to collect, steal, or corrupt your company’s data. 

Outsider threats exploit your system’s vulnerabilities using a diverse range of tools such as phishing, spoofing, ransomware, and others. We’re going to discuss some of the most prominent threats along with some top email security tips:   


Phishing is one of the most prevalent email threats in cybersecurity. It’s a method to infiltrate large companies by using social engineering techniques to steal sensitive business information. Phishing emails have a certain level of sophistication. That’s why it’s so easy to fall prey to them. 

These legitimate-looking emails often target low-level executives and include some form of attachment or link. When the victim clicks on these files, the attackers deliver malicious payloads to their systems.

Your company needs to consider the importance of data loss prevention (DLP) strategies, one of which is education. Awareness is the best way to prevent these email threats. If you suspect a phishing attack, pay close attention to the emails you receive and read them carefully. 

Check the sender’s email and make sure there are no changes in the structure of the address. Implement strict policies regarding the content of emails in your organization and interactions with attached files.


Spoofing is often considered the ugly brother of phishing and is among the top-ranked email security threats. Spoofing is a deception carried out via email, phone, fraudulent websites, or messaging applications. Attackers play the role of a trusted source to the victim. 

It can be a supervisor, member of the IT team, or even a high-ranking executive inside the company. The goal is to make the victim relinquish sensitive information or perform actions such as an electronic funds transfer. 

Many spoofing attacks are used as middle points to carry out larger attacks. Most of the time, cyberattackers use spoofing to scam companies out of money.

As with phishing, you can prevent spoofing by informing and training employees on email security issues. . One of the best ways to avoid spoofing attacks inside a large organization is by implementing strict communications policies. 

Employees should never comply with unusual requests if these do not follow specific parameters. Make sure your team understands how to handle information internally and externally. When it comes to funds transfers, make sure there’s a proper protocol for approvals involving the higher-ups. 

Business Email Compromise (BEC)

BEC attacks are some of the most dangerous email security risks you can face. A business email compromise is a thoroughly sophisticated attack. Cyber actors gain access to the email account of a high-ranking company executive or forge their way in. 

The results are indistinguishable from the emails you get by traditional means, meaning many people fall for these attacks. BEC attacks have a 97% efficiency rate, and there are very few defenses against them. 

BEC attacks stand out from all types of email threats because they play to a sense of urgency with the victim. The impersonator can even use a trick domain that passes a quick visual inspection. BEC messages appear to come from someone with a high rank within the organization, asking for something unusual. 

BEC scenarios are more psychological than technical, so employees must know how to identify such attacks and confirm unusual or suspicious instructions 

A multilayered data protection plan can also help mitigate BEC attempts. Use encryption software, VPNs, and multi-factor authentication to protect your company’s flow of communication.  

Directory Harvest Attacks

Directory harvest attacks are another external email security threat. In these attacks, spammers find all valid email addresses related to a  domain. Attackers then gain access to your email infrastructure and take hold of all addresses associated with your company. 

DHA events are carried out using brute force means or by guessing company email addresses using the permutation of commonly used usernames.

The best defense against DHA is a mail protection service. These solutions use software that integrates with your email infrastructure. The program constantly monitors your data flow and sends reports of suspicious or unusual activity.


Ransomware is one of the most popular email security threats in the present day. With this technique, cybercriminals send attached files or links that look legitimate totargets inside an enterprise’s network. 

Once the victim interacts with these, the payload delivered is a piece of malicious software that spreads quickly and locks you out of your system. The attacker then asks for money in return for a decryption key to regain access.. Ransomware attacks are usually well-coordinated; they’re designed to affect entire networks instead of a single terminal.

The best defense against ransomware is a solid data leak prevention strategy. Regularly patch and upgrade all operating systems. Make periodic backups of crucial company data and install the latest antivirus and firewall solutions. Lastly, implement protocols on how employees must handle attachments of any kind. Only valid and safe files and URLs should be opened or clicked.

Insider Threats

Data breaches can happen internally too, either by accident or with intent. We call insider email security threats any attack originating within your company. Insider attacks are usually carried out by disgruntled employees, industrial spies, or accidentally in the absence of proper IT support. 

Human error plays a significant role here. Lack of awareness about appropriate defense protocols can lead to massive exposure to cyber threats. Here are some of the most prominent challenges big companies face and how to solve them:

Configuration Errors

A widespread email threat in cyber security is failing to configure your email server or email security service properly. A configuration error can lead to a severe drop in your reputation as a sender. It can get you blacklisted and lead to miscommunications with your clients and business partners. 

You can leave several backdoors wide open for cybercriminals to access your network without requiring any form of authentication. This can lead to a complete hijacking of your domain and a serious number of scams associated with your company’s name.

The configuration of an email server is a complex task that should be managed by professionals. The best way to deal with configuration errors is to make sure they don’t happen in the first place. 

Third-party services such as Office 365 and Google Workspace offer user-friendly configuration schemes. If you’re unsure of how to set them up, ask your IT team to step inm or hire a cybersecurity company.

Disgruntled Employees

Someone no longer happy to work in your company increases all email security risks. It’s important to understand employee perceptions and address their pain points effectively. Talk to their managers and ensure they pick up any form of dissent or discontent. 

Sometimes, a disgruntled employee retaliates by leaking data using any means they have. They can send delicate information to an outside email address or extract data using portable devices. 

There aren’t many ways to prevent these inside threats other than keeping track of anybody that stands out for being problematic. If this person proves too disruptive, the IT department should block their access to all systems until HR figures out how to approach the situation. It’s not an elegant solution, but it helps to safeguard all your data.  

Lack of Email Authentication

Without your email domain authenticated, your company is exposed to various email security threats. A ruined brand reputation, loss of credibility, a lower deliverability rate, and financial losses are just some of the consequences.

You can authenticate your email by setting up three policies: SPF, DKIM, and DMARC. They work in conjunction to make your domain more secure, allowing only legitimate company emails to reach recipient inboxes  

You’ll prevent bad actors from taking hold of your domain and spoofing addresses to send spam, phishing, or any other fraudulent messages under your company’s name. DMARC policies establish a series of rules to authenticate messages between two servers. The domain owner defines these rules. 

It’s a rather complicated process but with EasyDMARC’s user-friendly solutions and expert assistance, you can authenticate your domain in no time. 

Get started by scanning your domain with our free domain scanner to check for possible phishing vulnerabilities and SPF, DKIM, and DMARC record issues. Our platform offers various tools to generate, maintain, and analyze these records to keep your domain secure.

By getting your domain authenticated, you can constantly supervise your email flow and learn how each message you send performs against filters.

Final Thoughts

Email threats in cyber security aren’t going anywhere. However, education and preventive plans can significantly reduce such risks. 

Outsider threats are the most common methods of attack. Teach your employees everything about phishing, spoofing, BEC, DHA, and ransomware attacks. Many of these events are preventable, but you can only mitigate them if your employees recognize the signs and know what to do from there.

Insider threats are caused by human error or bad intent. That doesn’t mean you can’t prevent them too. Have your email infrastructure configured by a professional. Keep an eye on disgruntled employees, and authenticate your domain for the utmost protection. 

Go one step beyond the usual recommendations and use mail protection services. Install a firewall and antiviruses and keep updated backups of your data in the cloud and servers.

Various authors from EasyDMARC teams have contributed to our blog during company's lifetime. This author brings everyone together.


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