[Greylist-users] greylisting for exim
mjd at digitaleveryware.com
Sun Jun 22 12:43:50 PDT 2003
I decided to give greylisting a try. The only problem is the sample
implementation is in perl for sendmail using sendmails milter interface. I
use exim as my MTA which is completely different. So I wrote a "C"
implementation for exim based on the specification (not the perl code) and
integrated it into exim using exims local_scan interface (intended for
interfacing to virus scanners). I used the exact same mysql database layout
since it was easy and probably a good idea to stay compatible.
Due to the way local_scan works in exim, all rejections are after the DATA
phase. I don't think this is totally a bad thing since it costs spammers
bandwidth which is a critical item for them. While real MTAs will also have
to use a little more bandwidth to get the initial message through, I think
that won't cause too many problems.
I'm currently testing my version on a low volume secondary mail server to do
some QA and gain some experience with greylisting before moving it to my main
machine and domains. When I'm conviced there are no bugs, I'll be happy to
make it publicly available to anyone wanting to use greylisting with exim.
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