Frequently Asked Question

DKIM is important for security. Google has recently made it a requirement if you are sending group emails to multiple gmail accounts. They are also requiring DMARC. You will need access to whom ever manages your external DNS entries as you will have to add a couple CNAMES.

Follow these instructions:

https://learn.microsoft.com/en-us/microsoft-365/security/office-365-security/email-authentication-dkim-configure?view=o365-worldwide