I wanted to share with you my journey to setup an smtp relay server (copiers, fax, voice mail notifications, etc. ) and what I finally found that made it work:
If you are using a Shoretel system make sure that you have notificaitons on, a valid email, and the SMTP relay server set (Sites -> HQ -> SMTP Relay)
You will also want to follow step three to install IIS on a server:
You can follow through that entire article if you need to send to domains that you don’t have authoritative control over.
Once IIS is setup right click on the default SMTP virtual server and make sure that authentication is set to anonymous and relay has the devices you want to to be able to send mail.
Make sure you adjust the limit size for larger attachments, a fax might exceed this limit of 10MB.
Set Outbound Security as pictured below, Outbound Connections to TCP Port:25, and the smart host to be where your mx records are pointed to. This is usually yourdomain.mail.protection.outlook.com. You will also find alot of references to podXXXX.outlook.com or smtp.office365.com. These might also be valid choices for you.
Add a remote domain with your domain name and finish.
Under the properties of the domain now listed choose ‘Allow incoming mail to be relayed to this domain’ and ‘forward all mail to smart host’. This value will be the same as the smart host you listed above.
You can see mail go into the queue here and then disappear. If it stays there you have a problem:
Easy tool to test whether relay is working: