Problems with Outlook express mail

Starting today, my outlook express has been coming back with an error with my password ( Password was rejected, Authentication failed, port 110, 0X800CCC90 and 92 ) . I can send out mail from Outlook Express to my other e-mail accounts, but cannot send mail to my Outlook from Hotmail or Yahoo.  I get this fatal error with the code 550.5.1.1 ..Anyone else having this problem ?

 

Dim 4400 ( 2002 )
2.6 Ghz
Bios A06
768 MB DDR 2100
Windows XP Home
SP-2
1703 FP LCD monitor
PC-Cillin Security.....Much better than Nortons