当然， Postfix 很棒。

但您考虑过这些开源替代方案吗？

它们是免费的，可自托管的，并由社区驱动。

自己检查一下：  Stalwart .

  1. 所以是 Stalwart

    All-in-one Mail & Collaboration server

    ★ 10.2K Mail Collaboration Calendar License: AGPL-3.0

    Stalwart is an open-source mail & collaboration server with JMAP, IMAP4, POP3, SMTP, CalDAV, CardDAV and WebDAV support and a wide range of modern features. It is written in Rust and designed to be secure, fast, robust and scalable.

    preview