How can you secure your email server?

2 Encrypt your email messages and connections

Encryption is a process that converts your email messages and connections into a code that only authorized parties can read. Encryption helps prevent unauthorized access, interception, and tampering with your email data. There are two main types of encryption that you can use to secure your email server: transport layer security (TLS) and end-to-end encryption (E2EE). TLS encrypts the connection between your email server and the recipient's email server, while E2EE encrypts the message itself from the sender to the recipient. You should enable both types of encryption on your email server and use secure email clients and protocols that support them.

3 Authenticate your email identity and domain

Authentication is a process that verifies your email identity and domain, and prevents others from impersonating you or sending emails on your behalf. Authentication helps protect your reputation, deliverability, and credibility, as well as reduce spam and phishing attacks. There are three main types of authentication that you can use to secure your email server: sender policy framework (SPF), domain keys identified mail (DKIM), and domain-based message authentication, reporting, and conformance (DMARC). SPF validates the IP addresses that are authorized to send emails from your domain, DKIM signs your emails with a digital signature that proves your ownership, and DMARC specifies how to handle emails that fail SPF or DKIM checks.

4 Update your email server and software regularly

Updating your email server and software is a crucial step to secure your email server, as it helps fix any bugs, vulnerabilities, or compatibility issues that may affect your security or performance. You should always install the latest patches, updates, and upgrades from your ESP or software vendor, and test them before applying them to your production environment. You should also monitor your email server and software for any anomalies, errors, or breaches, and report them to your ESP or software vendor as soon as possible.

5 Configure your email server and software properly

Configuring your email server and software properly is essential for optimizing your security settings and preventing any misconfigurations or mistakes that may expose your data or compromise your functionality. Therefore, it's important to follow the best practices and guidelines from your ESP or software vendor, and customize your email server and software according to your needs and preferences. Some of the common configuration tasks you should perform to secure your email server include setting strong passwords that are changed regularly, enabling multi-factor authentication and limiting login attempts, restricting access and permissions to authorized users and devices, disabling unused or unnecessary features and services, using secure ports and protocols for email transmission and retrieval, filtering and blocking spam, phishing, and malware emails, as well as backing up and restoring your email data regularly.

6 Educate your email users and staff

The last step to secure your email server is to educate your email users and staff, as they are the ones who interact with your email server and software on a daily basis. You should train them on how to use your email server and software safely and responsibly, and how to avoid or respond to any security threats or incidents. You should also create and enforce a clear and consistent email policy that outlines the rules, expectations, and consequences for your email users and staff. You should also communicate and update your email policy regularly, and solicit feedback and suggestions from your email users and staff.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?