Hoi folx,
we have the problem that we receive a lot of spam with sender addresses
e.g. @hotmail.com but the mail is relayed via open relay mailservers
(not on e.g. mail-abuse RBL).
I think it would not be too hard to hack qmail-smtpd to check for the
existance of e.g.
/var/qmail/control/knownsmpt/hotmail.com
in case the sender domain is hotmail.com, read from the file a list
of IP addresses and accept the mail, if TCPREMOTEIP is on the list
or deny it otherwise (hard or temporary, one's milleage may vary).
Has anyone done something like that?
Any comments (pro/con) on doing somthing like that? (I know it is some
additional maintenance effort, but maybe one could convince the "big
mail hosters" to provide such lists for download?)
\Maex
