OT - Greylisting (was: Re: gOCR SpamAssassin plugin)

[Jim Holland]

On Sat, 12 Aug 2006, Julian Field wrote:

> Kevin Miller wrote:
> > Michael Baird wrote:
> > 
> >> Greylisting decreases load immeasurably on a mailscanner system, the
> >> cost of greylisting is much less then allowing the message to go
> >> through the mailscanner sytem. I deployed it several months ago, it
> >> really is a good tool, and I've had very few complaints (10000 users).
> > 
> > I just use Sendmails greet pause which is 10 seconds to set up and works
> > a treat - does greylisting add significant control or improvement over
> > that?  Anybody using them in tandom or is one or the other to be
> > preferred?
> 
> I use both, and I have had to turn the greetpause setting down to about 
> 2 or 3 seconds, as some systems (such as NTMail) don't check properly 
> for the welcome message before sending the HELO or EHLO. At that sort of 
> setting, it has little benefit. And there is no easy way to set up a 
> whitelist with greetpause.

I just put "GreetPause:<ipaddress> 0" entries in the access file before 
the default entry.  See sendmail notes:

	If FEATURE(`access_db') is enabled, an access database
	lookup with the GreetPause tag is done using client
	hostname, domain, IP address, or subnet to determine the
	pause time:

		GreetPause:my.domain    0
		GreetPause:example.com  5000
		GreetPause:10.1.2       2000
		GreetPause:127.0.0.1    0

Regards

Jim Holland
System Administrator
MANGO - Zimbabwe's non-profit e-mail service