I have a situation where there are several ISPs running open relays,
which are being used by spammers to hit users at this site. I'd like
to find a way to reject mail that's passed through these ISPs'
mailers, regardless of what the envelope sender is. IOW, something
sort of like badmailfrom, but which looks at the names/addresses of
the mailers which have handled the mail along the way.
Some digging in the qmail docs and sources didn't turn up anything
quite right. A bit of web surfing suggests that maildrop might do
what I want, but it looks like I'd have to spend some non-trivial
amount of effort. Anybody have solutions or suggestions?
Thanks in advance...
