MX records
MX records show which mail exchangers are published for receiving email for a domain.
What .auDO observes
The published mail-exchanger set
.auDO records public MX answers and compares changes over time. Email-provider classification is a separate best-effort inference derived from these and related visible patterns.
Technical fields
Why it is observed
Mail routing is visible infrastructure evidence
Why it matters
MX records provide routing context for email-provider movement and mail posture when read with DMARC, SPF and TXT evidence.
What visible change may mean
A change may reflect mail-provider migration, filtering or routing changes, reseller configuration, cleanup or maintenance.
Interpretation limits
Mail routing does not describe the whole mail control environment
MX presence does not establish active use, delivery quality or complete authentication posture. Provider attribution remains an inference.
Common retained observations
Mail-exchanger change
Where to use this evidence
View mail-routing posture and dated movement
Related concept
What MX records reveal
Related signals