Balancing compatibility and security

SpamHero provides opportunistic TLS encryption so that email communications between mail servers will be encrypted where possible. That means that when a sender uses TLS encryption to send email to a domain that is using SpamHero filtering, we will also attempt to use TLS encryption to deliver filtered mail to the final destination server.

Want to enforce TLS connections?

You can setup a policy that instructs senders to only deliver mail to your domain over a TLS connection. However, the policy is only enforced by senders that support MTA-STS. For more details, see: Advanced Email Security with MTA-STS