mailing list bounces

[tdiehl@rogueind.com (Tom Diehl)]

On Sun, 30 Oct 2005, tek@undergroundinfection.net wrote:

> I don't remember when i got these but at some point in the past week or so
> i received these messages in my mail log report:
>  1     1.30  66.92.236.195 does not like recipient./Remote host said: 450
> <bclug.org-request@lists.sitelink.com>: Recipient address rejected:
> Greylisted for
> 300 seconds (see
> http://isg.ee.ethz.ch/tools/postgrey/help/lists.sitelink.com.html)/Giving
> up on
> 66.92.236.195./
>  1     0.58  66.92.236.195 does not like recipient./Remote host said: 450
> <bclug.org@lists.sitelink.com>: Recipient address rejected: Greylisted for
> 300
> seconds (see
> http://isg.ee.ethz.ch/tools/postgrey/help/lists.sitelink.com.html)/Giving
> up on
> 66.92.236.195./
>  1     0.77  66.92.236.222 does not like recipient./Remote host said: 450
> <tdiehl@rogueind.com>: Recipient address rejected: Greylisted for 300
> seconds (see
> http://isg.ee.ethz.ch/tools/postgrey/help/rogueind.com.html)/Giving up on
> 66.92.236.222./
>
> Anyone have any ideas on how to go about making them disappear?

You should not see them any more. Apparently the above message was sent to
both me and the list. They are both from my mail servers. ;)

I use grey listing for spam rejection. Every time a mail server connects to
one of my mail servers, my mailserver checks a db for the following info:
    1.  The IP address of the host attempting the delivery
    2. The envelope sender address
    3. The envelope recipient address

If the above triplet is not in the db then the mailserver returns a 450
try again later response code. This tells a "properly configured mailserver"
to try again. When the "properly configured mailserver" trys again the
db is once again consulted. If it has been more than 300 seconds (5 minutes)
since the last attempt then the message gets delivered, unless of course there
is some other rule that causes it to be rejected. Fortunately by the time a
message hits grey listing most of the other checks have allowed the message
through. ;)

A large amount of spam generating mail servers will never try again. If you
are seeing actual delivery failures, as opposed to just log entries I would
suggest you fix your mail server as it is broken. Send details here if you
need help fixing that.

For more info about greylisting have a look here:
http://projects.puremagic.com/greylisting/whitepaper.html

Hope this helps.

Regards,

Tom