- Email Domain Health: What IT Admins Should Be Monitoring (MX, SPF, DKIM, DMARC, and Sender Reputation) Your sending domain is infrastructure you own, not a one-time setup. Here's what MX, SPF, DKIM, and DMARC actually check, why a domain can have all four configured and still be failing, and where to watch sender reputation.
- Why Adding an Email Signature Can Break DKIM and S/MIME (And How to Avoid It) Adding a signature after a message is cryptographically signed can invalidate that signature. Here's exactly why DKIM and S/MIME break, and the test that proves whether your tool does it.