Okay, so here's my situation:

I needed a bigger hard drive, so I slaved my old one and installed a new primary master. I installed Slackware 11, configured it, and transferred all of my data off of the old drive. So far so good.

Everything is running fine except for the fact that from outside of the LAN, all of my ports seem to be blocked (it's not even replying to ping requests). This had not been a problem on the previous drive, which was also running 11.0, but it had been upgraded version by version from 10.0.

Ordinarily, I'd just play with the configuration until I figured out how to solve this, but this machine's my mail server, so it's semi-urgent that I get it running again quickly.

Any suggestions?

have u make sendmail listening on external interface rather than 127.0.0.1?

Actually, I figured it out about 10 minutes after I posted my question. It was a firewall misconfiguration. I can't believe it took me so long to find it. ><

Thanks for the help though.