[Mimedefang] VERY Newbie Question

[Alexander Dalloz]

Am Fr, den 29.10.2004 schrieb Yang Xiao um 18:10:

> Won't this check generate a lot of false positive if the sending host
> has a hostname that's different from it's public DNS name? I have had
> several mailhost like this in places I've worked before, it's not
> because we are lazy or careless, but because it's very hard to change
> the hostnmae for various reasons.

I see only spam attempts being rejected. To speak freely, a mail server
administrator who does not setup his server properly, means the server
hostname / IP fits both the forward and reverse DNS entries, is
responsible himself if his wrong setup leads to rejected mails. In times
where SPF and other methods to reduce spam delivery I feel it is a
central job to take care a mail server can't be mistreated as a
suspicious machine.

> But as to my problem, I just want to stop anybody from sending to the
> mail gateway as local domain users because it's a incoming spam filter
> mail host. I guess I would just need to check for MAIL FROM header
> somewhere? But where should I implement this check in MIMEdefang? and
> do you see any senario that it will break anything?

From your more recent posting I see you are on the right way. You will
have to think which parameter combinations ($sender, $recipient, $helo,
$ip, ...) do fulfill requirements for a scenario you want to block by
rejecting the mail. filter_recipient in the mimedefang-filter would be a
proper place to do so. See "man 5 mimedefang-filter". It is an example
for a very good man page and has examples. You can find a lot of other
code when going through this list's archive. 

> Yang

Alexander


-- 
Alexander Dalloz | Enger, Germany | GPG key 1024D/ED695653 1999-07-13
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