--On 27 January 2011 09:29:36 +0000 David Angleitner
<David.Angleitner@???> wrote:
> I found in RFC 1869, SMTP Service Extensions:
> "A client SMTP supporting SMTP service extensions should start an SMTP
> session by issuing the EHLO command instead of the HELO command."
>
> "should start a session" is not required. So I'm not sure
> if this behaviour is against the RFCs.
RFC 1869 predates RFC 2119 by about 18 months, so "should" isn't well
defined in 1869. Were it well defined,
"there may exist valid reasons in particular circumstances to ignore a
particular item, but the full implications must be understood and
carefully weighed before choosing a different course."
I guess the full implications here are that the client should not worry so
much if it can't start TLS when it doesn't know whether the server supports
TLS. If the client is an MTA, then it really should not care. If it is an
MUA, then it should care, and should do all it can to comply with the
relevant RFCs. In any event, it's hard to imagine a good reason for
ignoring the recommendation.
--
Ian Eiloart
IT Services, University of Sussex
01273-873148 x3148
For new support requests, see
http://www.sussex.ac.uk/its/help/
