This is my first time adding a new domain in exchange 2007.
I have been following this guide on adding a new domain to exchange
Internal email work and I can send out external email ok.
When I try to send in an email externally from gmail or hotmail however I get this error message
Remote-MTA: dns; [10.4.126.40]
Diagnostic-Code: smtp; 5.1.0 - Unknown address error 550-'5.7.1 Unable to relay' (delivery attempts: 0)
Email come in through an ironport and then are routed to netscalers, the ip address above is the netscaler. They then load balance the mail to the exchange servers.
Any help would be appreciated.