ETRN

from The Free On-line Dictionary of Computing (8 July 2008)

ETRN

   <messaging, protocol> ("Extended {TURN}") An {ESMTP} command
   (first defined in {RFC 1985}) with which a {client} asks the
   {server} to deliver queued mail to the client via a new ESMTP
   connection.

   ETRN supersedes the {SMTP} "TURN" command in the same way that
   ESMTP's "{EHLO}" supersedes SMTP's "{HELO}".

   (1997-11-21)