How to find Postfix version

Executive Summary

The version of Postfix running on a system is not retrievable from the command line by passing an option (e.g. -v | --version) rather through the configuration tool.

Solution

The version of Postfix running on a system is not retrievable from the command line by passing an option. In other words, the following will NOT work.

[user@server ~]$ postfix --version

This is because Postfix is a bundle of daemons (services) and not a single process application. In order to determine which version of Postfix is running on a server, it is necessary to query using the postconf tool.

[user@server ~]$ postconf mail_version
mail_version = 2.10.1