Maybe the authentication (with or without SSL) is wrong. Carefully check your account data.
If all fails, see if Thunderbird (another e-mail program, free download from mozilla) does connect. If so, join the millions of WLM-users who switched.
I have a problem with Windows Live Mail. I can access my mail online but in WLM my password is not accepted. I tried reinstalling but the problem remains. What to do?