submit is a daemon-less mail transfer agent for multi-user Unix systems, implemented in Python. In contrast to other MTAs, it moves the configuration of non-local mail delivery away from system administrators and towards the individual users. Notable features are:

• sendmail(8)-compatible command line interface.
• Support for SMTP and Sendmail transports: submit can relay mails through smarthosts as well as interface with other sendmail programs (such as those provided by Postfix, Exim or the original Sendmail).
• Synchronous delivery: When submit returns successfully, you can be sure that your mail is out.
• SSL/TLS support, including CA- and fingerprint-based validation of the server’s identity and certificate-based authentication.
• Pluggable interfaces (currently GTK+ and TTY) for authentication.
• Optional daemon process storing SMTP passwords and passphrases to private keys.
• Optional support for different delivery methods depending on the sender address selected in the mail client.

A user’s manual is available.

submit is distributed freely under the terms of the MIT/X license.

The latest release is 0.2; you can grab a source tarball, a Debian source package or a Debian binary package built for Sid on May 10, 2012.