--On Tuesday, 30 January, 2007 12:26 -0800 "william(at)elan.net"
<william(_at_)elan(_dot_)net> wrote:
On Tue, 30 Jan 2007, John C Klensin wrote:
You don't want to do it on QUIT -- too many systems, in
practice, send QUIT and view _any_ response as "ok". However,
there is already provision for returning error replies at the
end of the DATA command (i.e., after the CRLF.CRLF). Such
replies are actually necessary with errors like "SIZE limits
exceeded" (the reply code isn't called that, of course) and to
deal with other problems and MTAs are expected to cope with
them.
How does server know if client is or is not going to ignore
reply after DATA?
The server doesn't, any more than the server knows that the
client isn't going to ignore responses to MAIL or RCPT commands.
However the protocol clearly requires that the client pay
attention to those codes. Paying attention to reply codes after
sending QUIT is much less certain, because it is not clear what
one would do with those codes. Certainly one cannot negotiate
further with server about them, since the server has not
obligation to read the input stream after acknowledging the QUIT.
john