To authorise Sophos to send emails on your behalf of your domain, add their mechanism to your SPF record. 

The mechanism for Everbridge mail is:

include:_spf.prod.hydra.sophos.com

Detailed steps, and mechanisms for other SPF can be found below.

For information on enabling DKIM on your Sophos gateway please contact Sophos support.

To test your configuration for both SPF and DKIM is correctly configured, start your 14 day free trial with OnDMARC!