Author: Heiko Schlittermann Date: To: exim-dev Subject: Re: [exim-dev] [Bug 1066] interpret some 4xx error codes from
remote server as permanent errors (5xx). Sometimes the Postfix MTA returns
4xx error when mailbox does not exist
Andrey N. Oktyabrski <ano@???> (Do 13 Jan 2011 08:43:01 CET): > ------- You are receiving this mail because: -------
> (In reply to comment #3)
> > Agree. Not a good feature.
> I agree too: this feature is not good. But this Postfix behaviour is really
> annoying. What I can do with "4xx mailbox does not exist" response? Add another
> HDD for my outbound queue? Maybe we need the configuretion option something as
> "wrong_4xx_workaround" in transports? Why we have the "helo_allow_chars" option
> (which is really needed in the real world) but cannot do anything with wrong
> smtp codes?
It is not wrong on the postfix side, it is wrong with its
administrators. Postfix is just the wrong tool in the wrong hands.
The above behaviour is some postfix feature which has to be enabled by
the admin. The intention is to give the admin a 2nd++ chance in case of
accidential rejects. Some admins tend to misunderstand this feature.
I think, having a special retry rule for rcpt_4xx (or probably they even
have a recognisable specific 4xx) should be sufficient to protect the
own queue and to notify the sender sooner than normally.
But in general, it's not our responsiblity to decide (or to find out),
if that '4xx mailbox does not exist' is real or fake.
