I want to defer some messages in the ACL for RCPT. As there's no
way (as far as I know) of explicitly deferring messages from an
ACL, I'm using a condition which expands to something like
`:defer: User over quota, try later' if I don't want to accept the
message at that time.
It seems that the message string is only honored if you reject the
message with 550, and specifying the message after the :defer:-
magic was the only other way that I could find any reference to in
the specification.
This works only partially; Exim prints 421 in the SMTP dialogue, but
with the message `Temporary local problem - please try later'.
So, what am I missing here?
By the way, any solution that requires verify = recipient is out
of the question, as it costs too much to (attempt to) route all
incoming messages regardless of their validity - it will load the
database and the NFS server too heavily.
