Milter-greylist

Matthieu Herrb <matthieu.herrb@...> wrote:

> I seem to remember that I've heard Emmanuel talk about implementing 
> greytrapping, but I've not seen it discussed here. I've tried to 
> implement that in mimedefang, but there are some drawbacks that could be
>   avoided by using milter-greylist for that.

How are you going to store the blacklist? IMO, a reasonnable approach
would be to match the messages using milter-greylist ACL, then feed a
DNSRBL. 

You'd need to add a DNS update action clause to milter-greylist ACL,
something such as:

dnsrblupdate "MYRBL"  ns.example.net  127.0.0.10
racl blacklist rcpt wzizo1at5ti.fsf@... dnsrblupdate "MYRBL"

You'll also need to think about entries expiration. What do you think?


Your other proposal (matching messages that goes to secondary MX before
primary) seems a bit more difficult. MX sync may help: the messages you
want to match arrive at secondary MX without being already greylisted.
It seems you need to add an information to the greylisting database:
where the message was presented last time (IP of MX for instance).

-- 
Emmanuel Dreyfus
http://hcpnet.free.fr/pubz
manu@...