John C Klensin wrote:
I've assigned Issue 17 to the question of whether, if reply
lines constitute a continuation set, all of the codes are
expected to be the same and whether this needs clarification.
RFC 2821 currently says:
In many cases the SMTP client then simply needs to search for a line
beginning with the reply code followed by <SP> or <CRLF> and ignore
all preceding lines. In a few cases, there is important data for the
client in the reply "text". The client will be able to identify
these cases from the current context.
(bottom of Sec. 4.2.1)
It's clear to me that clients are permitted only to use the last reply
code and ignore all others. It's also clear to me that it doesn't
make sense to allow different reply codes in different parts of a
multiline reply, because a client is permitted to ignore all but the
last reply code.