messaging, protocol (LMTP) A protocol designed as an

alternative to ESMTP for cases where the mail receiver does

not manage a queue. LMTP is an application level protocol

that runs on top of TCP/IP. It was initially defined in

RFC 2033, and uses (with a few changes) the syntax and

semantics of ESMTP. It should be used only by specific

prior arrangement and configuration, and it must not be used

on TCP port 25 (the SMTP port).