MSN Messenger

Firewall... Yahoo can bypass firewall normally or through proxies (in preferences) Messenger needs a different port available through the firewall to have access.

Signing In to Windows Messenger by Using .NET Passport
Microsoft .NET Passport is a single service that allows you to use one e-mail name and one password across microsoft.com-affiliated sites and a growing number of participating Web sites across the Internet. If you have a .NET Passport, you only have to remember one sign-in name and one password. After you sign in to one participating site, you can sign in to other participating sites. Additionally, you can store information about yourself in your .NET Passport sign-in profile so you do not have to retype it when you visit participating sites.

A .NET Passport helps provide security. A .NET Passport helps protect your information by using powerful encryption technology and comprehensive privacy policies, and you are in control over which sites have access to the information that is stored in your passport, including your e-mail and mailing addresses, except as described in the .NET Passport Privacy Statement. .NET Passport also takes steps to help protect your privacy on public or shared computers. For example, when you sign out, all your .NET Passport-related personal information is deleted from the computer.

Troubleshooting Issues with .NET Passport
If Windows Messenger displays "yourusername@yourdomain (E-mail Address Not Verified)" for your display name and you cannot change it, you have not verified your e-mail address with .NET Passport. When you sign up for a .NET Passport, a verification e-mail is sent to the e-mail address you registered with .NET Passport. You must click the link in this verification message to verify your e-mail address. If you did not receive this message or if you deleted the verification message, follow these steps to have another verification message sent to you:
Visit to the following .NET Passport Member Services Web site:
http://memberservices.passport.com

If Windows Messenger does not recognize your .NET Passport, visit one of the following Microsoft .NET Pas

you should update msn messenger in :
http://windowsupdate.microsoft.com

I got it! Just don't used or unchecked the proxy server. Hence, i closed my question.

This question was closed by the author