On Fri, 10 Apr 1998 17:06:19 -0400 Mike_Gagnon(_at_)iris(_dot_)com
wrote:
On the other hand, draft-ietf-drums-smtpupd-06.txt has this to say:
Server implementations MUST support VRFY and SHOULD support EXPN.
For security reasons, implementations MAY provide local installations
...
is supported. Since they were both optional in RFC 821, they MUST,
if supported, be listed in the response to EHLO if service extensions
are supported.
Gaak. This is simply wrong, and the editor will go find his
sword and fall on it. The text in section 5 of RFC 1869
(STD 10) is authoritative and VRFY is not listed as an
extension/option because it is required. It will be
corrected in the next version of the cited I-D.
The theory here was that VRFY was promoted to "required" by
RFC 1123, which was a long time before we did the ESMTP
work. And, for what I hope are obvious reasons, we wanted
a conforming 821/1123 server implementation to be able to
conform to ESMTP simply by recognizing EHLO and returning
what it would have returned to HELO... that meant no
listed response for required functions.
john