Being frustrated with the spam filtering/handling of our present email hosting service,
I decided to setup our own smtp/mapi server.
We have a fractional T1 service with a static IP serving the WAN (public Internet) interface of our Linksys SOHO Router/Firewall.

I set up the Linksys Router to pass on any packets going to ports 1 thru 1000 to the LAN ip of our Fedora server where I have setup Sendmail and Cyrus2 for the smtp and mapi servers respectively. I have also forwarded some ports in the higher numbers.

I have had much difficulty trying to get this arrangement to work. The problem seems to stem from DNS. There seems to a conflict arrising from the naming of the domain.

The cyrus-imapd seems to be working OK. The problem is with sendmail. I can send mail out OK, but when someone replies to the email, sendmail cannot recognize the userx in the string userx@foodomain.com even though userx is an established mapi account. And the result is a relaying denied because of the unknown user.

I am sure there is a simple solution here since this is a typical arrangement. Any ideas on how to set up sendmail.mc to get this to work?

I would like MS outlook or Mozilla thunderbird email clients in our LAN to be able to send and receive email from the Fedora server. Many Thanks.