Here's the scenario…
With a fresh install of pfSense, i didn't had any problems with MSN Live Messenger. Then I installed IMspector believing that I can log MSN Chats. When I noticed that it was not that effective, I removed it. After a few hours I get a lot of complaints from our staffs saying that they can't connect to MSN anymore. So I tried opening the tcp port 1863 outbound, but had no luck. I've tried it for myself with all ports open, still was not able to connect to msn live. Finally, I've tried to install IMspector again, then voila, they can all connect to MSN without the hassles, even if the tcp port 1863 is blocked.
Any ideas why IMspector has to be installed for MSN to work?
Try turning on UPnP under services, but do understand the security implications of doing so before hand. Assuming it is currently off, I suspect this will correct your issue.
I was unable to get IMSpector to work either…any known issues?
I was able to fix my issue… I've reinstalled IMSpector and saw that the settings are still intact, so I disabled IMSpector and uninstalled it, then MSN worked :)