ESMTP is a user configurable relay-only Mail Transfer Agent (MTA) with a sendmail-compatible syntax. It's based on libESMTP supporting the AUTH (including the CRAM-MD5 and NTLM SASL mechanisms) and the StartTLS SMTP extensions.
ESMTP does not receive mail, expand aliases or manage a queue but can deliver mail locally via an MDA.
This package provides the regular MTA programs.