I'm the maintainer. Hermes SEG started as an AGPLv3 secure email gateway and has grown into a self-hosted email platform: a full Dovecot 2.4 mail server with mailbox hosting, Nextcloud built in for Files/Mail/calendars/contacts, Authelia SSO (TOTP/WebAuthn/Duo), an end-user portal, and a web admin console, wrapped in SpamAssassin and ClamAV filtering, S/MIME + PGP + TLS + encrypted-PDF encryption, at-rest mail-crypt, and DMARC/DKIM/SPF/ARC. Run it as your whole mail stack, or in front of an existing MTA (Postfix, Exchange, Google Workspace) as a security gateway. Docker Compose, on Ubuntu/Debian/RHEL/Rocky/Alma or whatever runs latest Docker and Docker compose.

Why: self-hosting mail usually means assembling Postfix, Dovecot, a spam filter, a groupware/webmail app and SSO yourself, then maintaining the whole thing and keeping it secure. This is that stack integrated that includes security you would otherwise pay Proofpoint/Mimecast/Barracuda per mailbox for.

As far as the business model is concerned, the Community Edition is free under AGPLv3 and is the complete product, not a demo. There's a paid Pro tier with operational add-ons that businesses and MSPs would care about like time-of-click link protection, a firewall/IPS UI, org-wide signatures/disclaimers, LDAP auth. Self-hosters don't need it, unless you want it ;)

On AI, since it always comes up. The project predates the current AI tooling by years. I used Claude on the Docker release for code review, optimization and planning, and it's credited as a contributor in the repo.

Happy to get into architecture if you wish. Feeback and questions are welcome. Thanks!