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.
- Exchange Online
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 (Add a domain).
More details on additional Advanced Security features provide as part of Microsoft Defender for office can be found here (Evaluate Microsoft Defender for Office 365).
Message ID: MC291056
Published: 12 October 2021
Updated: 19 October 2021
Effective: October 14, 2021