Recently, when I've re-added a 'require verify =
sender/callout=5s,maxwait=30s,fullpostmaster,defer_ok' to my ACL, I
noticed that some of the mails are rejected because the sender's mail
server refuses to accept mail with <> as origination.
Is there a way to make the MAIL FROM:<> to be replaced with some valid
address? I was thinking about using something like MAIL
FROM:<verifycallout@???> where verifycallout as an alias to
:blackhole:.