How do I troubleshoot error messages in Outlook 2003?

[Guest]

My email account through outlook has the yahoo small business mail server
names. Everyone's email in my office is working fine, but i keep getting
every message over and over. my inbox has 494 messages in it and they are
all duplicates of about 4 emails. the error code is 0x800CCC90 and it says
problem retrieving message, internal error. I have done all I can do to get
this fixed, it doesn't make sense as to why everyone else's outlook is
working and we all have the same settings and server names. PLEASE HELP
ME.................

 

[Guest]

That error indicates some sort of authentication problem.

http://support.microsoft.com/kb/298944/en-us
XADM: Error Message Cites Logon Problem and Password Rejection When You Try
to Connect Through POP3 Client

http://support.microsoft.com/kb/236032/en-us
Outlook Express and Outlook repeatedly prompt you for your password

Try those to see if either help