Re: Reject spam from my own domain

On Tue, 31 Jul 2007, NetComrade wrote:

> We have whitelisted our domain, but now we have spam coming from
> users that claim they're in our domain.
>
> What's the best way to fight it?

How exactly did you "whitelist your domain"? whitelist_from is a last resort even though it's the most appealing. You really want to use whitelist_from_rcvd or whitelist_from_spf.

Publish SPF records; that will help you out as well as everyone else.

If you can guarantee that mail addressed from your domain will only ever originate at your mail server, you can put some mechanism in place in the MTA to reject any message with your domain in the From envelope address unless it originates in your local network. How you do this depends on which MTA you use.

I can make suggestions for sendmail; another place to ask if you deside to do this would be the mailing list specific to your MTA.

--
 John Hardin KA7OHZ                    
http://www.impsec.org/~jhardin/
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