I have created a distribution group in win SBS 2k3 server (Exchange 2k3) which works fine for internal users but for external users they get the following error:
"Technical details of permanent failure:
Google tried to deliver your message, but it was rejected by the recipient domain. We recommend contacting the other email provider for further information about the cause of this error. The error that the other server returned was: 550 550 Rule imposed mailbox access for firstname.lastname@example.org refused: user invalid (state 17)."
I have set the setting to receive emails externally however i still get error messages.
Any help would be great.