What Is an SSL Certificate for an Email Server?

Have you heard of SSL mail server certificates? Here’s what you need to know

“An SSL/TLS certificate for an email server? Aren’t SSL certificates used for websites?”

If you can even remotely relate to either (or both) of these questions, you’re not alone. Many people have the misconception that SSL certificates are just for websites. Well, it’s easy to understand considering that SSL and website security have become synonymous.

However, SSL/TLS certificates are more capable than most people realize. One of the uses of SSL/TLS certificates is to protect email servers by securing data in transit. When they’re used as such, they’re often referred to as “mail server certificates.”

Let’s decrypt (excuse the pun) what they are, what they do, and how they work.

How Website Security and Email Security are Kind of Similar

Let’s start with a simple question: What do email servers do? Now you’d say, they send, receive, and store emails. Well, read the previous sentence once again and focus on the words “send and receive.” Now you get the point, don’t you?

Just like web servers, email servers also send and receive a lot of data. Unlike a web server, though, this data consists of email-related data rather than website data. Nonetheless, it’s DATA! Wherever there is data, there is a concern of data integrity and security. And wherever there is data in transit, there is SSL (well, almost everywhere).

Encrypting Emails and Encrypting Emails are Two Different Things

No, we’re not trying to confuse you here. For many people, “encrypting emails” means encrypting emails when they’re transmitting between servers. And for some, “encrypting emails” means encrypting them when they’re stored on the server. Well, if you’re holding either of these two beliefs, you’re not wrong.

However, as we can see, they both are two totally different things. We need to encrypt emails when they’re at rest on the web server to ensure that no one can see them and tamper with. And at the same time, encrypting emails at rest isn’t enough, so we must make sure that any email communication taking place through web server is encrypted to protect against man-in-the-middle (MiTM) attacks.

Why Email Security Should Be Your No. 1 Priority

Emails are and have been hackers’ favorite points of entry in organizations that they want to target. That’s because of two things. First, there’s a lot of incentive there as a significant amount of crucial organizational communication takes place through emails. And secondly, attacking/capturing emails is the most convenient route for an attacker to get inside any organization.

The latest email trends report by Barracuda shows that, on average, more than four-fifths (82%) of organizations claim to have faced an attempted email-based security threat in the past year. And 66% of organizations claim that attacks have had a direct monetary cost on their organization in the last year. Nearly a quarter say attacks have cost their organization $100,000 or more!

Now you see why email security should be your first priority for security?

S/MIME vs SSL for Email Security

Some organizations already use S/MIME certificates (sometimes referred to as “soft-tokens”) on their email accounts. This, undoubtedly, is a good thing. However, this is where most organizations stop. The thing about these certificates is that they’re issued to individual email accounts and, as a result, they encrypt emails residing in that particular account. However, they don’t facilitate encryption for email being sent and received from an email server.

That’s where an SSL certificate for email server enters the fray.

When you install an SSL/TLS certificate on mail server, it ensures that the data being sent and received through the email server is encrypted. Also, they ensure that the email server that you’re trying to communicate with is the intended server. This virtually eliminates the possibility of an attacker trying to fool your server by spoofing as another server.

Another benefit of using an SSL certificate for a mail server is that it also allows users to log in to their email securely. If you don’t have an SSL certificate in place when you log in, you’re essentially sending your plaintext credentials across the internet for any cybercriminal to intercept and read. Now, they have access to your account and to all of the data and information stored there.

An SSL certificate for email is a digital certificate that encrypts the emails in transit and authenticates the legitimacy of the sender.

S/MIME + SSL = Best Email Security

There’s no place for ”ifs” and ”buts” when it comes to email security of organizations. You must tighten all the loose ends that could result in only God knows what. That’s why, to ensure basic email security inside your organization, we recommend protecting your organization through S/MIME and SSL/TLS certificates.