iRedMail

iRedMail is a full-featured, open-source mail server solution based on Postfix and Dovecot. Licensed under GPL-3.0, it is intended for people and organizations that want to use an open-source email server rather than rely on a paid email product. It brings Postfix and Dovecot together as the basis of the server, providing an alternative for those looking to replace Gmail with software they can run as their own mail server. The main difference from Gmail is that iRedMail is a mail server solution, not simply the Gmail product. The available information does not specify which Gmail features have direct equivalents in iRedMail, so users should not assume complete feature-for-feature parity. It also does not describe administration, deployment, or maintenance requirements. iRedMail is therefore best evaluated as a GPL-3.0 email server built on established mail-server components, rather than as an exact open-source copy of Gmail.