Hello!
I've hit a brick wall.
I'm trying to figure out how to add an outgoing/outbound SMTP filter to
an Exim 4 configuration. Basically I want to perform a few checks on
mail before it is sent.
At the moment I have:
remote_smtp:
driver= smtp
transport_filter = /usr/mysillyscript
mysillyscript checks that the From: header is actually a domain
belonging to someone on the system. If it isn't it outputs "" to the
standard output, else it's output what it received. This works sort of,
except the message is still deliver just "blank" as it appears Exim does
not do anything useful with the result returned from the filter (such as
not deliver the message).
If there another way to do basic filtering on outgoing messages, whereby
if certain conditions are met (or not met) then the message is either
delivered or /dev/null routed.
Basically I have 100+ web hosting accounts on one of our servers, and
any trusted user can easily forge the "From: " header etc..., I want to
be able to stop this.
I have to admit I am a novice at Exim, so any help would be greatly
appreciated.
Matt Freeman
http://www.spenix.com
mattfreeman@???
