Should you be concerned about email security? What are some of the biggest email threats? How do you defend your organization against them? These questions may have crossed your mind, so, in this article, I will try to address them and also provide you with some email security best practices.

Email has remained a core part of our everyday digital life, even despite the rise and increasing popularity of instant messaging and collaboration tools. In virtually all industries, email is an integral part of regular business practices. The massive number of organizations that routinely use email can be linked to its simplicity and overall utility.

Approximately 306.4 billion emails have been exchanged daily in 2020 for both business and private purposes and the number is projected to reach over 361.6 billion emails sent every day by 2024, so it’s no wonder that emails have been a desirable target for cybercriminals for some time now.

How Secure is Email?

Just like any piece of technology, email in and of itself is not secure. Today’s email usage differs greatly from what its inventors initially expected.

The invention of email is credited to Internet pioneer Ray Tomlison (yes, the same one who also contributed to the development of the first experimental computer virus, whom you may have already read about on our blog), bringing about “a complete revolution, fundamentally changing the way people communicate”, as The Internet Hall of Fame puts it.

But why isn’t email completely secure?

Much like most legacy technologies, email was not designed with security in mind. For instance, just as you need to ensure Secure DNS for your organization, you also need to make sure you are using Secure Email.

Even though the inherent protection of email has quite increased since its creation, it is still far from being a fully protected communications medium of exchanging sensitive data.

Should you and your organization want to avoid becoming the protagonists of yet another email-related internet crime story, keep on reading and find out how you can stay protected.

What is Email Security

Email security alludes to the joint safety measures employed by an organization or individual to protect an email service or account and ensure secure access and communication.

Gartner defines “email security” as follows:

Email security refers collectively to the prediction, prevention, detection and response framework used to provide attack protection and access protection for email. Email security spans gateways, email systems, user behavior, and various supporting processes, services and adjacent security architecture.

Email security should be approached as a multi-layered concept, which combines employee education, robust cybersecurity policies, and proper security tools.

How Email Security works

Email security is based on technologies that examine and/or encrypt incoming and outgoing emails to safeguard its users and the data they share and protect them from various cyber incidents.

Email security gateways

Secure Email Gateways provide protection by stopping threats before they arrive on an email server, defending organizations from email-based cyber threats and social engineering attacks – or in other words, from Business Email Compromise (BEC). These gateways scan all inbound and outbound email traffic for potentially infected attachments and malicious URLs, as well as investigate the domain of the incoming emails and block them, if necessary (or quarantine them for later inspection conducted by IT administrators).

Email Security Gateways provide many advantages for enterprises, offering protection against email dangers such as spam, malware, and phishing attacks. Since a company’s personnel may oftentimes prove to be one of the attackers’ main targets, using a Secure Email Gateway will enable organizations to enhance their protection by scanning and filtering malicious emails and preventing email-related cyber incidents.

For instance, HeimdalTM Security has developed two email security software aimed against both simple and sophisticated email threats (MailSentry Email Security, which detects and blocks malware, spam emails, malicious URLs, and phishing attacks and MailSentry Fraud Prevention, a revolutionary email protection system against employee impersonation, fraud attempts – and BEC, in general).

Heimdal Official Logo

Email communications are the first entry point into an organization’s systems.


is the next-level mail protection system which secures all your
incoming and outgoing comunications
  • Deep content scanning for attachments and links;
  • Phishing, spear phishing and man-in-the-email attacks;
  • Advanced spam filters which protect against sophisticated attacks;
  • Fraud prevention system against Business Email Compromise (BEC);
Offer valid only for companies.

Top threats to Email Security

Below you can find the top three email security issues you should watch out for:

#1. Phishing

Phishing, the malicious practice employed by cybercriminals, which involves sending emails pretending to come from legitimate entities in order to trick people into sharing sensitive information such as their login credentials or credit card numbers represents one of the major threats to email security.

Attackers will often circumvent technological security protection measures and target an organization’s users directly. When not properly trained to recognize the tell-tale signs of phishing attacks, employees will easily fall prey to phishing attacks.

At the beginning of 2020, Wandera revealed that every 20 seconds a new phishing site was being launched. What’s more, according to Barracuda Networks, as soon as the COVID-19 pandemic emerged, there was a 667% spike in email phishing attacks in March 2020.

#2. Spoofing

Email spoofing attacks are based upon the creation of emails that appear to be coming from a genuine email address, when in fact they were sent by malicious actors. In this case, the attackers’ ultimate purpose is to fool the recipient into opening the message and, for instance, download an infected attachment.

In other cases, email spoofing can turn into elaborate BEC schemes that can take months to unfold and often lead to huge monetary losses. Recently, a US-based company became the victim of an email-based scam and lost $15 million. In short, after the attackers managed to gain access to an email account that belonged to the organization, they created email forwarding rules to make sure they received the messages from the targeted email inbox so that they would never lose access. After intercepting the communication between senior executives, eventually, they requested a fake money transfer.

Email spoofing is feasible since a mechanism for address authentication is not established by the Simple Mail Transfer Protocol (SMTP). While protocols and methods for email address authentication have been developed to combat email spoofing, the implementation of such frameworks seems to be slow.

#3. Malware

Malware involves any harmful software intended to communicate with, damage, or obtain unauthorized access to a device. Without a target’s consent, malware may execute different malicious functions, such as encrypting, deleting, exfiltrating confidential data, or tracking users’ behavior. Viruses, worms, Trojans, ransomware, or spyware, to name a few, are different forms of malware that can hide in emails.

Commonly, malware can be inserted into email attachments or in phishing links.

Malware threats are getting more and more advanced and challenging to fight. In order to infiltrate and weaken IT systems, attackers often use sophisticated social engineering techniques. Critical data can be stolen if a device is hacked, and significant harm can be done if an intrusion goes unnoticed.

Email Security Best Practices

It’s crucial that you and your users take all the necessary steps to ensure the safety of your email accounts against attacks and impede all unauthorized access.

How do you protect your organization against email threats? Here are some important suggestions:

  • Run regular phishing tests

Your personnel is your greatest protection against email threats, especially when it comes to phishing attacks – be them simple or more sophisticated, such as spear-phishing. This significant risk of endpoint compromise can be avoided by staff who have learned to recognize phishing attempts.

  • Always use multifactor authentication

In case the passwords of an email account are successfully compromised, multifactor authentication will deter malicious hackers from accessing the account and severely affecting your business.

  • Block email auto-forwarding

You should also consider blocking email auto-forwarding to make it harder for threat actors to gain access to your corporate email accounts.

  • Use email security software

Secure encrypted email is always a good idea when it comes to securing the content of your emails and preventing them from being read by parties other than the intended recipients. However, this practice alone will not suffice. Thus, you also need to consider an integrated cybersecurity solution, able to detect basic and advanced forms of email attacks.

Did you know that 35% of client organizations that move to Office 365 are forced to supplement its natively available email security capabilities with a third-party product?

For example, you may want to consider HeimdalTM Security’s MailSentry Fraud Prevention, the ultimate email protection against financial email fraud, C-level executive impersonation, phishing, insider threat attacks, and complex email malware.

How does it work? By using over 125 vectors of analysis and being fully supported by threat intelligence, it detects phraseology changes, performs IBAN/Account number scanning, identifies modified attachments, malicious links, and Man-in-the-Email attacks. Furthermore, it integrates with O365 and any mail filtering solutions and includes live monitoring and alerting 24/7 by our specialists.

Heimdal Official Logo

Email communications are the first entry point into an organization’s systems.


is the next-level mail protection system which secures all your
incoming and outgoing comunications
  • Deep content scanning for attachments and links;
  • Phishing, spear phishing and man-in-the-email attacks;
  • Advanced spam filters which protect against sophisticated attacks;
  • Fraud prevention system against Business Email Compromise (BEC);
Offer valid only for companies.


Email security should always start with having the appropriate security measures in place, such as encryption, multi-factor authentication, advanced cybersecurity tools, and last, but not least, human vigilance. Make sure you follow these recommendations so you can put an end to email security threats.

How do you handle email security in your organization? Leave us a comment in the section below!

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