I've just spotted a couple of cases where the envelope-sender's
MX record looks up to "mail." E.g
# host -t mx medicalsavingzrus.com
medicalsavingzrus.com mail is handled by 0 mail.
Is there an obvious way to reject such envelope-senders in an ACL
(I mean, without resorting to a hand-coded DNS lookup within the
ACL conditions), please? The way things are at the moment, exim
is reporting:
Could not complete sender verify
due to the non-callout "verify = sender" that we're using - and
issuing a _temporary_ error, and the abuser (or their compromised
relay) are retrying over and over.
thanks
