M365 Changelog: Simplified DKIM configuration for email protection

MC291056 – Updated October 19, 2021: Microsoft has updated the content below with additional details. Thank you for your patience.

Domain Keys identified mail (DKIM) is part of email authentication mechanism which ensures the email is not modified during transit and can be used to validate the visible sender (FROM address) as part of the DMARC standard. By correctly configuring authentication through DKIM you can ensure better email deliverability and protect your domain from being spoofed.

As part of Microsoft’s continuous effort to help organizations configure email authentication, they reduced the complexity involved in configuring DKIM to set of simple steps.

When this will happen:

The feature is live, and you can visit the DKIM configuration page https://security.microsoft.com/dkimv2 or https://protection.office.com/dkimv2 to enable DKIM for your custom accepted domains, DKIM is already setup for the default domain automatically. Further details can be found in this document 

How this will affect your organization:

If DKIM is already enabled for your custom domains, there is nothing you need to do.

By default, Microsoft signs all messages with DKIM for all outgoing email from your tenant. When no DKIM setting is available for a custom sending domain the default tenant.onmicrosoft.com domain is used to sign the message. This updates makes it easier for you to change this configuration so that the DKIM signing domain is based on the custom domain enabling better email authentication. You can enable DKIM by following simple steps mentioned here 

Once enabled, any outgoing email your tenant will automatically be DKIM signed using your custom domain.

What you need to do to prepare:

It is recommended that DKIM is configured for all mail sending domains. To configure DKIM for a domain, the domain needs to be part of accepted domains of your tenant. All the accepted domains of your tenant will automatically appear on DKIM page, if you wish add additional domains to your tenants follow the steps mentioned here

More details on additional Advanced Security features provide as part of Microsoft Defender for office can be found here.