Fedora Users — Fedora core 1 sendmail problems

I have been searching the archives of this list and google and not yet found the solution to my problem. It seems like this is a common problem with sendmail on new installations of Fedora, so I am frustrated by not finding a solution that works for me. I would really appreciate any help.

I had a RedHat 7.3 installation working properly, both sending and receiving mail with sendmail. I wanted a clean Fedora install, and since then I can send, but not receive mail.

I have modified /etc/mail/sendmail.mc and commented out the line dnl # DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA')dnl then ran make -C /etc/mail and restarted sendmail with service sendmail restart.

I also modified /etc/mail/access and added
localhost.localdomain           RELAY
localhost                       RELAY
127.0.0.1                       RELAY
myserver.mydomain.org   RELAY
then restarted sendmail.

I have a 4 port linksys as a router/firewall between my cable modem and my server (and 2 other PCs). Port forwarding is enabled on the linksys to allow http traffic, and smtp on port 25 to be forwarded to the server - which was all working correctly before the Fedora install.

I ran ethereal and watched connections, not that I understand much of the packet info. I see connection attempts, but external mail servers never complete a connection. The typical pattern seems to be a remote server sends a SYN on port 25, I reply with SYN,ACK. Remote sends a SYN, I send 2 SYN,ACKs. Remote sends a SYN, and I send 3 SYN,ACKs, and eventualy the rmote gives up.

From any PC inside my network I can telnet to the server on port 25 and

issue basic smtp instructions. I can do the same locally with 127.0.0.1 e.g. # telnet myserver.mydomain.org 25 Trying 192.168.1.12... Connected to myserver.mydomain.org. Escape character is '^]'. 220 myserver.mydomain.org ESMTP Sendmail 8.12.10/8.12.10; Sun, 28 Mar 2004 11:41:01 -0500 mail from: someone@xxxxxxx 250 2.1.0 someone@xxxxxxxxxx Sender ok rcpt to: homer 250 2.1.5 homer... Recipient ok data 354 Enter mail, end with "." on a line by itself Subject: test message this is a test