After a year of development, the new stable branch of the mail server Postfix – 3.12.0 has been officially released. The announcement also includes the end of support for the previously released Postfix 3.7 branch, which was made available in early 2022. The project’s code is written in C and distributed under the Eclipse Public License (EPL 2.0) and IBM Public License (IPL 1.0).
Postfix stands out as a project that incorporates high security, reliability, and performance simultaneously. This achievement is attributed to its multi-process architecture, which isolates individual handlers. Additionally, the project adheres to strict code design and patch auditing policies. To prevent errors when working with memory, Postfix utilizes protected variants of functions for memory allocation and deallocation. It also employs a set of abstract binding functions for various operations such as file handling, output formatting, buffered I/O, and string manipulation.
According to the final automated survey of approximately 500 thousand mail servers (with reports ending in July 2025), Postfix is being utilized in 37.88% of mail servers, up from 36.81% in the previous year. Other popular mail servers include Exim with 55.59% usage, Sendmail at 3.55%, MailEnable with 1.81%, MDaemon at 0.40%, Microsoft Exchange at 0.20%, and OpenSMTPD at 0.12%.
The main innovations in the Postfix 3.12.0 release include work on simplifying migration processes, as outlined in the official release notes.