Our data indicates Everbridge supports DMARC compliance via SPF.
Contact Everbridge to ask about their DKIM capabilities.
Everbridge advises to add 'include:everbridge.net' to your SPF record, however note this pulls in two additional includes. Although they also advise to use a subdomain (which would help a lot in avoiding the 10 DNS lookup limit), it's still worth getting in touch with Everbridge and understanding if there's a lesser authorization to use. More information on SPF setup: https://support.everbridge.com/articles/Documentation/Custom-Email-Notification-Sender-Information-Doc