maitred

Lightweight embeddable SMTP RFC5321 server for use in applications that need to receive e-mail.

The original goal of this library is to have a usable SMTP server that can be embedded in mailing list software, particularly for use in Ayllu and Mailpot. After considering all of the existing SMTP servers there was no Rust library that could be easily embedded in an application and general purpose SMTP servers like Postfix are too complex to be reasonably packaged.

Due to the common abuse of the SMTP protocol by nefarious internet actors the default behavior of this package must never allow open relaying without explicit and conscious configuration from the user. Additionally the SMTP server must never expose the e-mail addresses or other user data contained within.

This library does not implement any TLS termination nor does it allow for STARTTLS upgrades. The recommended production setting is to use an SMTP proxy server like Nginx to terminate TLS there.

NOTE: This library is at best in an “alpha” state currently and should be used for absolutely nothing that is important.

All authentication extensions are implemented with the mail-auth package from Stalwart.

Several of the free software libraries released by stalwart are in use here.