Cannot send emails outside of the domain

[200820]

This morning my companys email decided to stop sending emails to any address that is not part of it's own domain.

When anyone tries to send an email outside of the domain the following bounceback is received;

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

Subject:
Sent: 25/08/2009 16:45

The following recipient(s) could not be reached:

p***.*******8***@o*.co.uk on 25/08/2009 16:45
There was a SMTP communication problem with the recipient's email server. Please contact your system administrator.
<e****-c***.org #5.5.0 smtp;550 <p***.*******8***@o*.co.uk >... Relaying denied>

 

[Zelandakh]

Are you using an Exchange server as an edge server or do you go direct?

 

[Zelandakh]

Also, anything in the event log?

 

[200820]

We were just using the exchange server but I found the problem, a setting to filter out recipients that were not in the directory had been changed for some unknown reason, thanks for the help though

 

[Zelandakh]

Yes, that will do it.