Blacklisting by server hostname

[Jim Holland]

On Thu, 11 Mar 2004, Stephen Swaney wrote:

> > >Nowhere in the above files is there a mention of how to block by server
> > >hostname - which I consider most important.  I would like to be able to
> > >block mail from any host in, say, the namespace .client2.attbi.com, for
> > >example.  Will "*.client2.attbi.com" work?  All the examples however use
> > >e-mail addresses and not domain names, and *@*.client2.attbi.com is
> > >definitely not what I want.
>
> Your MTA is probably the right place to block by domain or server
> name. Uses lots less resources.

That is what I am doing at the moment.  However what I find is that
round-robin spammers will make numerous attempts to deliver to the target
address using a battery of different servers hoping to eventually get
through (making ten or more delivery attempts before they finally give
up).  I therefore sadly conclude that the best option is to accept the
junk in the first place as the attack is then over and done with, and then
to quarantine it from the end recipient using MailScanner.  There is also
the advantage that if the spam is in fact genuine mail the recipient will
be able to ask for it to be retrieved (they receive a daily digest of
messages that have been quarantined).

Regards

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