Postfix Starttls With Sasl Authentication How To

Securing email communication is of utmost importance in today’s digital age, where sensitive information is constantly transmitted over the internet.

Postfix, a popular mail transfer agent (MTA), offers a robust solution for ensuring the confidentiality and integrity of email messages.

Prerequisites and System Preparation

You need to make sure that you have the following requirements ready for an easy and fast process:

  1. A Linux-based server: For the sake of this article, we will assume that you have an active Linux server in your computer that serve as the email server.
  2. Installation: Make sure you have it installed and configured on your server. Otherwise, you can use the package manager to install it.
  3. OpenSSL: Ensure that OpenSSL is installed on your system, as it is essential for implementing StartTLS.
  4. Basic understanding of configuration files: Familiarize yourself with configuration files, such as and

Configuring Postfix for StartTLS

StartTLS is a protocol extension that allows email communication to be encrypted during transmission. To configure Postfix for it, you need to change the file. Add the following codes in the file:

  1. smtpd_tls_cert_file=/etc/ssl/certs/postfix.pem
  2. smtpd_tls_key_file=/etc/ssl/private/postfix.key
  3. smtpd_use_tls=yes

Make sure to replace the paths with the actual locations of your SSL certificate and private key files.

Implementing SASL Authentication

Simple Authentication and Security Layer or simply SASL is a framework that provides authentication and data security for various network protocols, including SMTP. To implement SASL authentication, follow these steps:

Install the necessary SASL libraries and utilities on your server. Configure this MTA to use SASL by adding the following lines to your file:

  1. smtpd_sasl_auth_enable = yes
  2. smtpd_sasl_type = cyrus
  3. smtpd_sasl_path = smtpd
  4. smtpd_sasl_security_options = noanonymous

Enabling StartTLS with SASL for Email Services

You need to integrate the previously configured settings to combine it and SASL for secure email services. Ensure that the following locations are in your file:

  1. smtpd_tls_auth_only = yes
  2. smtpd_tls_security_level = may
  3. smtpd_tls_loglevel = 1

These settings enable the use of it for authentication and encryption.

You have the power to encrypt your email correspondence and ensure that the exchange of data remains uncompromised. Remember to regularly update your system and configurations to avoid potential security threats.