SMTP Problem —This is urgent!

I can receive mails from anywhere in the internet. But when I send mails out it will remain in the queue for a while and return delay errpr mesage after which it will return a non-delivery error message after a two days. Check out this example:

Your message did not reach some or all of the intended recipients.

Subject: Good
Sent: 3/3/2004 5:52 PM

The following recipient(s) could not be reached:

‘sakintade@hotmail.com’ on 3/5/2004 6:07 PM
Could not deliver the message in the time limit specified. Please retry or contact your administrator.

please who knows how to go about this problem.