I have Exchange 2010 (on SBS2011)
When I send mail to user@mycustomer.com I get the follwing NDR 550 - Mailbox unavailable. The server response was: 5.7.1 Unable to relay
- All users can send mail
- I can telnet to the server i.e MX etc all ok, firewall rules ok
- I was using POP3 (inbound) and now trying to config server to be fully SMTP
- Users have mailbox with default recipient policy addr @mycustomer.com
- I have two Receive Connectors - domain.local & mycustomer.com
Is there some setting I am missing? DNS? Permissions?
Really pulling my hair out at this stage - please help
Thanks in advance