550 not local host yahoo.com, not a gateway

[deveshlal]

Whenever any user from local area network sends mail to out side lan, the mail bounces back with the following message-

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

Subject:
Sent: 10/1/2003 2:51 PM

The following recipient(s) could not be reached:

deveshl@yahoo.com on 10/1/2003 2:51 PM
The recipient name is not recognized
MSEXCH:IMS:CRISP:MAINDOMAIN:EXCHSERVER 3550 (000B0981) 550 not local host yahoo.com, not a gateway

Please suggest the possible cause at devesh@crispindia.com

 

[JonnyKu]

Don't just e-mail to him, Share and post the solution

My company is having the exact same problem

 

[demea26]

I'm having the same problem, but only when the Cisco IOS firewall v.12.3(2) is up, which isnt good for obvious reasons. When disabled, everything is OK.
Error message,
550 not local host accupac.com, not a gateway.

Its really driving me nuts because people are saying that the outgoing server requires authentication in Outlook properties, but is already being authenticated!

I dont know, any help would be appreciated.