SaaS

DCI / Gateway

What does this solution describe?

How to add an Office 365 (O365) domain to SpamTitan. 

What are the steps?

1.  Go to System Setup > Mail Relay > Domains and select Add... to add the new domain
   
   Usually, the destination server is in the following format: example-com.mail.protection.outlook.com (where your domain is example.com). See Add your Domain(s).
   
2. Click the test icon on the right under the Options column to verify the domain and that it is receiving mail from SpamTitan.
3. Set up Dynamic Recipient Verification on O365, so you can use it in SpamTitan:
   
   1. Enable Directory Based Edge Blocking (DBEB) in Office 365 so that it rejects invalid RCPT TO probes: https://docs.microsoft.com/en-us/exchange/mail-flow-best-practices/use-directory-based-edge-blocking 
   2. Enable Dynamic Recipient Verification in SpamTitan, and the Verification Server is the same as the Destination Server (i.e., the Office 365 FQDN) https://docs.titanhq.com/en/8911-more-about-recipient-verification.html. 
4. Add O365 IP ranges to your Trusted Networks Microsoft List (SpamTitan SaaS skip this step).
5. Check SpamTitan and Office 365 IP Throttling (Rate Limits).
6. Ensure Your Email is Not Marked as Spam in Office 365.
7. Set SpamTitan up as your only trusted email source by locking down your Office 365 email server. 
8. If filtering outbound email, you must also set up a connector on O365.