esmtp is a user-configurable relay-only Mail Transfer Agent (MTA) with
a sendmail-compatible syntax.  It is based on libESMTP supporting the
AUTH (including the CRAM-MD5 and NTLM SASL mechanisms) and the
StartTLS SMTP extensions.

Features include:
  * fully sendmail command-line compatible,
  * supports the AUTH SMTP extension, with the CRAM-MD5 and NTLM SASL
    mechanisms,
  * supports the StartTLS SMTP extension,
  * requires no administration privileges,
  * individual user configuration,
  * does not receive mail, expand aliases or manage a queue,
  * local mail delivery via a MDA.