> Essentially we want to control what undelivered notices we actually
> send. Any way to do this? Selectively choose what undelivered
> notices to send back to the original sender?
You can use a system Sieve filter to discard bounces that match
certain criteria, and you can use customized bounce messages to do
things like add special information or tracking headers. For example,
locally we drop all bounces of things that we scored as spam. Our spam
filtering system marks the original Subject:, so we copy the Subject:
into the bounce as 'X-Original-Subject' and then have a router that runs
bounce messages past a system Sieve filter that inspects them:
eat_spam_bounces:
driver = redirect
# only discard bounces going externally
domains = ! +local_domains
file = /magic/filter/file
allow_filter
allow_freeze
user = Debian-exim
no_verify
no_expn
condition = ${if and {{!eq{$interface_port}{25}} \
{!def:return_path} {def:h_x-original-subject:} }}
The Sieve filter itself is basically:
# Exim filter
#
if $h_x-original-subject: BEGINS "[PMX:SPAM] "
then
seen finish
fi
(with logging and some additional conditions and etc.)
What I don't know is how you'd get necessary information from the
text of the SMTP error into the bounce message in a way that a Sieve
filter could use here. But I haven't looked into this, since we haven't
needed it.
- cks
