Re: Anti-Spam ideas for usenet/list harvested email addresses (forpostfix mail admins)

["Jacob Anawalt" <jacob@cachevalley.com>]

daniel said:
> I found a nice web page which can give postfix mail admins some nice
> tips to block most incoming spam/mail bombs.
>
> I added most of the checking described in this url plus a 100Kb mail
> limit since nobody sends me more than that.
>
> Before I could be receiving 10 spam and/or mail bombs per 5 min.. now
> per 5 min. I am receiving none.. Im anxious to check how many do I
> receive tomorrow...
>
> This is the link - http://www.wsrcc.com/spam/
>
>

Thanks for the link, looks pretty sensible in their setup. I don't think
this rule is a good idea:

http://www.wsrcc.com/spam/bounce.html
[quote]
550 Client host rejected: cannot find your hostname, [168.126.3.59];

Here the sending site's DNS administrator forgot to put the name of the
host into the DNS system at all. Our system has no way to tell the name of
your host. This is probably the most common mistake.

There are two places the DNS administrator has to enter the information
for each host. One, the so called "forward mapping" maps the hostname to
IP address. Two, the "reverse mapping" maps the IP address to the
hostname. Both of these mappings have to agree for our host to believe the
information it gets.
[/quote]

This will reject email from many vaild and well managed mail servers who
aren't able to buy their own ip block or get an ISP who will do
reverse-dns for their mail servers.

-- 
Jacob
Trying out SquirrelMail