The problem must be somewhere else. Firewalls, at least the kind we associate with NAT routers, work by listening for outbound requests and always allowing return traffic. That means if your outlook contacts the mail server, the firewall should always allow the return traffic from the mail server... what I'm saying is its probably not the router and I'd guess not a software firewall.

That said, it sounds like you have at least 2 software firewalls running on your PC. I think thats probably overkill if its not the cause here, will lead to problems in the future.

There are some things you can do to test your connection....
open a command prompt (start-->run-->type "cmd" and click ok).
type "telnet <mail server address> 25" (where <mail server> is the name or IP of your outbound mail server). If you get a message that it timed out or other error, then your computer cannot reach the server. If you get connected and greeted with a strange prompt, then you have successfully connected.

If you are able to connect, you might try using another email client just for testing sake... Thunderbird is very lightweight and easy to setup. If that connects, then consider uninstalling and re-installing outlook, making sure to delete any settings in the process (google for it, not entirely sure where it puts all its tentacles).

If you cannot connect with that test, or thunderbird, the it sounds like there is a connection problem. Make sure other computers on the same network (IE, behind the same router) can connect. If they can, then its your computer specifically. You've already taken some good testing steps in disabling the two firewalls. You might want to actually uninstall the nvidia firewall (not sure what a graphics and chip company is doing making a firewall anyway)...theres a chance that even if disabled its done something funky to the TCP/IP "stack"...

by the way, I'm obsessed with Blink from eeye. software (http://www.eeye.com/html/index.htm) its free and its an amazing firewall, virus scanner, malware protector... you might remove your other software firewalls, making sure to reboot, and then try Blink...