Semi OT - Anyone doing greylisting?

[Andy Jezierski <aj...@stepan.com>]

Just curious if anyone is doing any greylisting on their systems?  If so,
have you noticed a dramatic decline in the amount of spam that gets through
to SA?  Sounds like an interseting concept that I'm thinking of trying out,
but thought I'd see if anyone had any comments about it first.

Thanks
Andy

Re: Semi OT - Anyone doing greylisting?

[Bill Landry <bi...@pointshare.com>]

----- Original Message ----- 
From: "Andy Jezierski" <aj...@stepan.com>

> Just curious if anyone is doing any greylisting on their systems?  If so,
> have you noticed a dramatic decline in the amount of spam that gets
through
> to SA?  Sounds like an interseting concept that I'm thinking of trying
out,
> but thought I'd see if anyone had any comments about it first.

I've been using postgrey with postfix for about a month now and it is
working very well for us.  We block roughly 40,000 messages per day/per
gateway by using greylisting, and this keeps us from having to accept the
entire message and then process it for spam.  This has drastically cut down
on both our bandwidth and server processor utilization.

I highly recommend greylisting.

Bill

Re: Semi OT - Anyone doing greylisting?

[Lucas Albers <ad...@cs.montana.edu>]

Kenneth Porter said:
> There's been some implementations using MIMEDefang that are reportedly
> quite effective. Check the MD list archives for the code to include in
> your
> MD filter. Or buy Can-It, the commercial version of MD, which includes
> greylisting and a bunch of other stuff.
>
I use greylisting in MD, see my comments on it in the archive.
It requires a little configuration.
Works well, you can also implement granular greylisting based on the spam
score, or helo/relay checks.
The commercial product can-it is easier to setup and fuller featured then
the open source version. It also does greylisting.

I believe postfix,exim4 also support greylisting.
-- 
Luke Computer Science System Administrator
Security Administrator,College of Engineering
Montana State University-Bozeman,Montana

Re: Semi OT - Anyone doing greylisting?

[Jonas Eckerman <jo...@frukt.org>]

On Tue, 22 Jun 2004 14:14:05 -0500, Andy Jezierski wrote:

>� Just curious if anyone is doing any greylisting on their systems?

Yes. You can find my implementation for MIMEDefang at:
http://whatever.frukt.org
�
>� If so, have you noticed a dramatic decline in the amount of spam
>� that gets through to SA?

Absolutely. And it stops some virii as well.

You can check some stats (go to the "totals" page) at the site I mentioned above. If you need help interpreting them, just ask.

>� I'm thinking of trying out, but thought I'd see if anyone had any
>� comments about it first.

There are some pitfalls. For example mailers that can't handle tempfailed recipients. :-/ If you read through my filter, some stuff worth thinking about (even if you're not running MD) are mentioned there.

Regards
/Jonas
-- 
Jonas Eckerman, jonas_lists@frukt.org
http://www.fsdb.org/

Re: Semi OT - Anyone doing greylisting?

[Kenneth Porter <sh...@sewingwitch.com>]

--On Tuesday, June 22, 2004 2:14 PM -0500 Andy Jezierski 
<aj...@stepan.com> wrote:

> Just curious if anyone is doing any greylisting on their systems?  If so,
> have you noticed a dramatic decline in the amount of spam that gets
> through to SA?  Sounds like an interseting concept that I'm thinking of
> trying out, but thought I'd see if anyone had any comments about it first.

There's been some implementations using MIMEDefang that are reportedly 
quite effective. Check the MD list archives for the code to include in your 
MD filter. Or buy Can-It, the commercial version of MD, which includes 
greylisting and a bunch of other stuff.