I can't send email with exchange 2000 server

[acung]

I can't send my email out of my exchange server. When I'm send an email it will be directly got an error message from the system administrator about relay denied...

he following recipient(s) could not be reached:

'aca_edan@yahoo.com' on 12/4/2003 12:35 PM
550 relay not permitted

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

Subject: testing again...
Sent: 12/2/2003 6:12 PM

The following recipient(s) could not be reached:

'mukcung@yahoo.com' on 12/2/2003 6:12 PM
550 5.7.1 <mukcung@yahoo.com>... Relaying denied. IP name lookup failed [202.73.110.120]

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

Subject: testing....
Sent: 12/2/2003 10:36 AM

The following recipient(s) could not be reached:

'mukcung@yahoo.com' on 12/2/2003 10:36 AM
554 <mukcung@yahoo.com>: Relay access denied

somebody help me please....I'm in big trouble now....
Many thanks before....

 

[rubby2003]

can you ping yahoo.com for starters?
if so are you using pop3 connector