Google Outbound Services Configuration Guide - Manual (Page 76)

Microsoft Exchange 2007 without an Edge Server (Smarthost method) 81
Test Outbound Mail
Check the mail queues of the mail server.
1. In the Internet Mail Service Properties select the Queues tab. Look for items
with a retry state which could indicate outbound mail delays.
2. Send a message from a mail client inside your network to an outside address.
You should see a line in the header email which indicates being received and
delivered by
exprodNobM.obsmtp.com , where N and M are numbers.
3. Test inbound mail to confirm normal functionality. Send a message from an
outside email address to an address on your service.