If you click Test Settings and it states the test message was sent successfully this indicates this issue is not with the RMAD console. If a test message can not be sent from the console, then the ErdServer.log should contain errors similar to the following:
[584:Main] Error The message could not be sent to the SMTP server. The transport error code was 0x800ccc13. The server response was not available
[1584:Main] Info Exit SendMailMessage (uncaught exception)
[1584:Main] Info Exit SendTestMail (uncaught exception)
If there are no errors in the log, this means that the console was able to connect to the mail server using SMTP and send a message. This indicates the issue is with the recipient or mail server and not the RMAD console as it was able to successfully send the SMTP message to the mail server. Check the mail server spam filters, the recipient junk mailbox and the mail server logs to try and determine why the mail message was not delivered.