I forget this every time I set up a new server.
When I set up database mail on anew server I usually get the message “Service Broker is not enabled on msdb. Do you want to enable it?” Clicking OK gives me an unresponsive SQL server. Running the command “ALTER DATABASE msdb SET Enable_Broker” runs forever with no message returned.
What I forget each and every time is that the SQL Agent is running. Checking the locks or running sp_who2 shows that my ALTER DATABASE is blocked by the process running the Agent. Simply stopping the Agent allows the statement to finish, whether from the query window or clicking OK in the dialog box mentioned earlier. Then I just restart the Agent and everything’s hunky-dory again.
Maybe now I’ll remember it.