This post is part of the Email Security Foundations series. What DKIM actually does DKIM stands for DomainKeys Identified Mail. Where SPF checks where a message came from, DKIM proves that the message hasn’t been changed while it was in transit. When you send an email, your mail server adds a cryptographic signature to the … Read more
If you run an on-premises Exchange Server or any Windows-based SMTP relay that sends mail to or receives mail from Exchange Online, then you might have a hard deadline coming up: March 22, 2026. Miss it, and you can risk breaking your mail flow, if the Root Certificates used by Exchange is not updated. What … Read more
I have often seen this error in scenarios with either multiple tenants or if an organization, has a need to do automatic forwarding of e-mails to specific recipients outside the organization (tenant). The error can be found during troubleshooting the message logs, on why a specific e-mail did not arrive at its destination, or if … Read more