We have a single sbs2008 running exchange.
Everything is working fine, apart from mail to a particular domain bounces back. The reported error is as follows :-
The recipient's e-mail address was not found in the recipient's e-mail system. Microsoft Exchange will not try to redeliver this message for you. Please check the e-mail address and try resending this message, or provide the following diagnostic text to your system administrator.
I have tried it from an external scource and the mail gets through OK. I presume there is a problem locally, but as all other mail is getting through to the other destinations, I am unsure where to start.
I have also check that our IP address is not on any black lists, and we are not.
The NDR mesage seems to indicate that the mail address is not valid at the destination, but we know that it is.
The message bounces back almost straight away, so again that lead me to believe that it was not leaving our domain.
Can anyone assist in tracking this problem down?