First question:
Has anyone else had this problem? I try to forward/open ports on my router but it keeps saying network cable unplugged, then it reconnects, then it does this over & over again every 1 or 2 minutes. I have tried resetting the router/modem and not sure why this is happening. I have a Linksys Etherfast® Cable/DSL Router BEFSR41 with latest firmware.

Second question:
I can't seem to connect to SMTP servers on port 25. Even servers that I know are running. I have no firewall installed and the XP firewall is disabled. I am using Knology as my service provider. Do some ISPs block connections to port 25 to prevent e-mail spamming? I'm trying to write an SMTP server and this is proving to be a big problem. I saw nothing on their site mentioning this but haven't tried calling them yet.

Any sort of help or advice is welcome.