Re: [Exim] SIZE param for callbacks?

Alan J. Flavell wrote:

> Just so we understand each other: there'd be no automatic retry (the
> mail would be refused with a 5xx). The issue is what happens when the
> would-be sender clears their inbox and then tries to send the mail
> again, agreed?

Yes, that was my point.

> I must say, I was quite intrigued when Chris brought this observation
> to my attention. It had never occurred to me to try the callback with
> SIZE. I can't help being curious as to what proportion of MTAs would
> make that distinction in their response.
>

None of the ones I manage, although that's a small number :-) None of
the systems I work on have quotas for their users, and even if they
did they would be LDA quotas (in Cyrus IMAP) and not communicated back
to Exim at recipient verification time, so this situation would never
arise. I suspect that many MTAs that the callbacks would connect to
don't have any notion of user quotas, because they aren't handling the
local delivery directly and they don't get quota information back from
the LDA.

If I was going to try something like this, I think I would want to
have a separate expiry time for callouts that failed for this reason.
My normal expiry times for recipient callout failures are fairly long
(2-3 days at least) and that hasn't caused any problems, but it sure
would in an overquota situation.