Re: [Exim] Reaction to rude 554 greeting

At 22:13 +0000 2003/03/17, Matthew Byng-Maddick wrote:
>On Mon, Mar 17, 2003 at 10:33:34AM -0500, Richard Welty wrote:
>> however, Giuliano, you don't seem to understand the RFCs at all.
>>
>> you fail to connect, or you get a 4xx, it's ok to go to the secondary MX.
>>
> > 5xx means quit now. that's it. end of story. that's what it's always meant,
>> so long as i can remember (my experience with SMTP goes back to 1982, so
>> that's how long i can remember.)

I do not know what Richard is meaning. He is not the only one to
associate "quit now" to 5xx code. This must be a semantic problem,
"quit not" is certainly what I would associate to 421 and "554 at
connect", but not to any other documented code (as far as I can tell).
My experience in SMTP does not go that far back, in 1982 (or was it
84?) I was writing Montecarlo programmes and making some use of VAX
MAIL. (Only a few years later I managed to take advantage of the
services of VXGIFT::MINT and be told off for that).

>You will also note, then, that the 5xx on connect or after the HELO has
>been illegal (other than the illegal argument) since about that time. This
>is for precisely this reason. (Remember: you MUST accept a postmaster@
>address).

but you know that "554 on connect" has been indeed introduced in RFC2821.

>
>If I can't send mail to postmaster, then your MX is breaking the RFCs, and
>therefore you can't expect RFC compliance from the other end.

RFC2821 states that postmaster is not strictly necessary if you send
554 at all connections openings... Understandable.

>If you think it's a sane thing to do, think again. It is stupid to do a
>rejection before RCPT under any circumstances.

I agree, nevertheless the RFC seems to give some consideration to
this 554_on_connect, I was only proposing a solution to a problem (if
you like "an interpretation").
My proposal was not to treat all 5xx as a 4xx, but was to treat 554
on connection effectively as 421 on connection + add a warning to the
postmaster (for configuration debugging). It was based on three
keywords: MX,timely delivery, and 554, all missing from RFC821. It is
time to leave 821 for 2821.

Giuliano