I have a bizarre issue where an Exchange 2007 server is unable to forward email to external contacts. I've added mail contacts and added them into the mail flow properties of a mail user, selecting to keep a copy in the users mailbox...
What happens is that I get an NDR with the following information:
Generating Server: server.domain.local
mail.btconnect.com #550 Not permitted
I've tested this by sending an email to email@example.com - I can see by using Outlook Web Access, the firstname.lastname@example.org receives the test message and then receives an NDR into the same inbox with the above error.
Any ideas please?