RFC 5321, "Simple Mail Transfer Protocol", October 2008Source of RFC: IETF - NON WORKING GROUP
Area Assignment: app
Errata ID: 1851
Status: Held for Document Update
Reported By: Alessandro Vesely
Date Reported: 2009-09-08
Held for Document Update by: Pete Resnick
Section 188.8.131.52. says:
There are circumstances, contrary to the intent of this specification, in which an SMTP server may receive an indication that the underlying TCP connection has been closed or reset. To preserve the robustness of the mail system, SMTP servers SHOULD be prepared for this condition and SHOULD treat it as if a QUIT had been received before the connection disappeared.
That text seems inappropriate in the RESET (RSET) section. It should presumably be moved to section 184.108.40.206. QUIT (QUIT), or, better yet, to section 3.8. Terminating Sessions and Connections.