Monthly Observatory Brief - September 2026

What stood out this month

1. A change in visible MX routing coincided with a change in its derived inbound mail-provider association: one structured MX-change row and one supporting provider-association row were recorded for the same panel domain. The observed MX set reduced from two targets to one, and the inferred association changed from two providers to one. This is one linked infrastructure observation, not evidence of a completed service migration or supplier change.
2. The panel recorded 31 RDAP status-change rows across 17 domains. Private review found temporary transitions and reversals among the observations. These are bounded registration-layer signals, not claims about registrant conduct.
3. At the final September observation, MX evidence was determinate for 98 domains and visible MX was observed for 94. SPF evidence was determinate for 97, comprising 83 single and 14 malformed SPF-record observations. A valid DMARC record was observed for 97 of 98 domains with determinate DMARC evidence.

September 2026 · fixed monthly panel.