Greylisting (WAS: Re: MailScanner ANNOUNCE: 4.57 released)

[Matt Kettler]

Michel van der Klei wrote:
> On Sun, 3 Dec 2006 01:42:02 +0200 Nerijus Baliunas <nerijus at users.sourceforge.net> wrote:
>> Hello,
>>
>> I still get message corruption which I reported a few days ago when
>> using Postfix with milter-greylist 3.0.
> 
> What are the big advantages of milter-greylist? I use postgrey in combination
> with mailscanner and i'm very statisfied with the results. AFAIK is postgrey
> the tool to use with postfix.
>  

milter-greylist uses a really nice and flexible firewall-like ACL syntax. Using
the ACLs you can have all kinds of criteria to greylist on, and different delays
for each criteria.

Constructs like this are possible (this is vaguely how my config is structured):

whitelist (internal hosts)
whitelist (some friends)
greylist (src in NJABL-DUL) 1 hour
greylist (src in XBL) 4 hours
greylist (some hostname regex) 1hr
greylist (some ip range) 2hr
blacklist (anything from: *@evi-inc.com)
	(legitimate evi senders whitelisted above)
whitelist (everything else)

This allows me to use greylisting, but only on hosts that "look bad" for some
reason.

Others use the time variations to greylist "bad" hosts for a long period of
time, and greylist everyone else for a shorter period of time.

It's all in what you need from it.