Why can't I send e-mail but can receive it?

I cant send email but i can receive .. help me with this outlook ...

• i;m facing this problem n i need to fix it.. i can receive but i cant send email.. it will show like this : Your message did not reach some or all of the intended recipients. Subject: bla bla Sent: 8/1/2008 2:01 PM The following recipient(s) could not be reached: '[email protected]' on 8/1/2008 2:01 PM 550 <[email protected]> No such user here .. no such user.. every my contacts that i want to send an email.. it will show also the same thing.. help me.. i'm using microsoft outlook 2003.. also when i test my account to my server .. test complete for outgoing n receiving.. help me.. tq

• Answer:

  What do you have for your outgoing (SMTP) and incoming (POP) email servers? It should be: plus.pop.mail.yahoo.com for incoming, and plus.smtp.mail.yahoo.com for outgoing.