When using the vacation facility of an Exim Filter, the envelope
address of a vacation response is the null user. This is a documented
feature intended to help prevent runaway message sequences. I am
noticing that more and more SMTP hosts are testing incoming mail with
an envelope address of the null user to determine if they are bounces
and quarantining any such messages that are not bounces. Presumably
this is an anti-spam effort. Obviously, this creates a problem for
incoming vacation messages. I'm just wondering whose problem this is.
Is this an Exim problem; or, are the receiving SMTP servers
misbehaving by quarantining these incoming messages?
Thanks for any input.
... doug
