Ingo Doerrie wrote: [mail filter which only works via. smtp question]
Does anybody have a sample configuration for me or can tell me the source of a documentation on the web?
First of all, your setup is a littlebit oversized maybe: You can put a Mailserver into your DMZ which recives mails for some Domains if you need and fetches mails with fetchmail from your two pop3 boxes. So all mail will centralized on your DMZ Mailserver. On the mailserver run Postfix with amavis as content filter. All mail coming from the internet, no matter if via smtp or fetchmail (fetchmail will reinject the mail via. smtp to localhost:25 or anything else you specify), or sent from your lan thru the mailserver will be scanned for viruses (and if you use amavisd-new for spam). Then you just allow from inside your lan mailconnections to your mailserver into the DMZ and nothing else. That will protect your lan from viruses, your users can filterout spam and you don't need to setup two mailservers (and protect your lan better, cause if you allow your DMZ Mailserver to send mails into your Lan, everyone who compromises your DMZ Mailserver will probably able to break into your lan, too!)
Thank you for your answers, passed to ingo@doerrie-net.de in advance.
done. HTH and happy easter, Sven