How to secure a mail server using encryption
I had originally written this tutorial for xmodulo.com SSL (Secure Sockets Layer) and its descendant TLS (Transport Layer Security) are the most widely used protocols for encrypting data that is exchanged between a server and a client. These protocols often use X.509 certificates and asymmetric cryptography. STARTTTLS is another method of securing plain-text communication. This protocol also encrypts data with SSL or TLS, but with the same port as the plain-text protocols, instead of using separate ports for SSL/TLS-encrypted communications. For example, IMAP over STARTTLS uses the same port as IMAP (143), while IMAPS (IMAP over SSL) uses a separate port 993. The previous tutorial describes how to set up a mail server running on Postfix and Dovecot, but the security aspect was not covered. In this tutorial, we demonstrate how to add security to a mail server through TLS/SSL-based encryption . Certificates needed for TLS/SSL can be self-signed, signed by ...