DMARC, SPF, DKIM, DNS, and the things that go wrong with all of them. Written by people who fix this stuff for a living.
A dangling DNS attack pattern that exploited abandoned cloud resources. We mapped it across the .edu space and confirmed remediation at GWU, Harvard, and others. Here's what happened, how it works, and what to check on your domains.
Read the post →A subset of DMARC RUA reports never reach the destination. Here's why — and what to do about it.
A two-week disclosure thread that ended with a partial fix and a longer technical write-up. Lessons for anyone running shared sending infrastructure.
Two systems racing to manage the same record. The fix is one of three things. Here's how to figure out which.
90-day disclosure timeline, end-to-end. What we found, how we reported it, what the response looked like, and what we'd do differently.