[Mimedefang] Tuning for taking mail from qmail - practically denial of service

[David F. Skoll]

On Fri, 16 Apr 2004, Alton Yu wrote:

> As some of your probably know, qmail sends a lot of mail at a time and does
> not do connection caching, so it'll just hit the box with 15 or so mails at
> a time if the mail is destined for that specific host.

> My mail server seems to keep running out of slaves every time the sender
> does a queue run and 1/2 of it doesn't finish, so it'll just take my box out
> momentarily for 5 minutes at a time.

Take a look at the new notification facility in 2.42.  When you run out of
slaves, you can add a firewall rule to reject connections on port 25.  That
makes qmail give up quickly without overburdening you server.

Sure, it still blocks others from connecting, but it's kinder on your
machine.

See man mimedefang-notify

Regards,

David.