Not sure why, but sendmail is no longer accepting connections originating from outside my box. If I'm logged into the box and telnet to 25, no probs, but from external, nodda. JJust as a background, I have loopback shut down, just using the external IP interface. Now, things have been working for the last few months since this box was brought on-line, and now, poof. No one has changed anything in the configs (I know, only I have the root passwd). netstat -an shows that it is infact listening to the port on the proper addy, just nothing is allowed in. I have a clean iptables, so no firewall restricting anything. I'm now stumped, after working for 16 hours, I have hit a huge wall...

Thanks in advance,
da_tibmeister

any entries in hosts.deny and hosts.allow?

Are other net traffic moving normally?

Alot of ISP's are starting to block the well know ports now-a-days for residential customers. Are you sure your ISP has not suddenly thrown a switch (so to speak) and is now blocking inbound TCP/25 requests?

hosts.allow and hosts.deny are both empty, as they have always been. Al other net traffic is flowing perfectly. Funny part about it is, I am the ISP LOL, so that isn't a concern on my part either. This is why I'm stumped.

I had to LOL myself. Thanks for bringing some humor to my morning.

If you are the ISP, then I can see why you are so concerned about getting this problem fixed. Unfortunately, you have tried (tested) everything I would have tested in trying to pinpoint this problem.

BTW: Have you tried running tcpdump on this system to see if inbound packets are actually making it to this server? Especially since you claim netstat -an shows sendmail is listening on port 25. Good luck!

Reverified netstat -an, and port 25 is sure listening, but now, tcpdump port 25 comes up with nothing, so it looks like the packets are dying somewhere before getting to my box. No I'm starting to get concerned, cause it ain't my box, it's something in-between......