Subject: RFC 1845

From: "Edward Hibbert" <[email-masked]>
Date: 19 Jan 1999 20:01:01 UT

Can someone tell me the relationship between RFC 1845 (521 
return code) and DRUMS?  My impression is that they clash, but 
I imagine that there is a long and frenzied debate about this 
which I am ignorant of.  

Edward Hibbert
DCL.

---

From: Robert Elz <[email-masked]>
Date: Wed, 20 Jan 1999 19:51:14 +1100

Date:        19 Jan 1999 20:01:01 UT
    From:        "Edward Hibbert" <[email-masked]>
    Message-ID:  <SCOFFMAIL-990119200101Z-577*/P=DCNET/A=TMAILUK/C=GB/@MHS>

  | Can someone tell me the relationship between RFC 1845 (521 
  | return code) and DRUMS?

I think you mean 1846.

  | My impression is that they clash, but 
  | I imagine that there is a long and frenzied debate about this 
  | which I am ignorant of.  

I don't think there's been much (or perhaps any) discussion at all.

It would be nice if 521 (more or less as defined) would work - unfortunately
right now, it doesn't ... too many implementations treat 5xx type error codes
returned at places where an error "makes no sense" (according to their
implementors) as if they were temporary failures ("they're clearly broken,
give them a chance to fix things - I will try again later").

I used to run a 521 mailer (for just the 1846 type reasons), but that
attracted so much traffic, where I would have expected almost none,
that I have reverted to an earlier solution which simply rejects all
recipient addresses, and pretty much ignores (ie: says "ok") to everything
else.   That one works much better in practice (though it is slightly
more complex to implement, as you actually have to parse commands to
understand what they are, instead of simply saying 521 at everything).

DRUMS is generally meant to be doing an update of 821/822, not incorporating
all the other mail related docs that have been written since those.  About
all it should be saying about 1846 related issues is that 5xx reply codes are
acceptable to *any* SMTP command, and that they always mean that the
particular command will never succeed, and so implementations should never
send one unless that is really what they mean, and on the other hand,
clients must always treat a 5xx reply seriously (and not try again).

Eventually we might perhaps reach a stage where 1846 is actually useable.

kre