Email Send-Recieve Problem

Hi,

I have a system with Win2k pro and Office 2k installed. Using Outlook Express for mailing. OE has two identity when i send mail from one identity to other i can recieve mails.However if mail is send to other people(same domain or other) people do not recieve mail but i can see mail in sent item.

I am wondering if this problem is with windows or OE.

Pls. help

With Regards
Siddhpal Singh Patel