Email diagnostics and inbox placement answer different questions
An email test at Siglumo can confirm receipt at its own receiver and show authentication, sending-IP history and available message checks. It does not observe a Gmail or Outlook recipient’s folder decision.
What a passed check establishes
A passing authentication or local rule check covers that check’s scope. It is not a prediction that every provider will accept or inbox the message. Historical counts and content labels are not calibrated inbox-success percentages.
What to do with a finding
Use specific evidence: inspect a named authentication failure, improve recorded low text contrast, or review a destination that returned a conclusive not-found response. An inconclusive HEAD response is not a broken-link verdict; a successful response is not a content-safety certification.
How to check placement separately
- Send from the actual campaign workflow to mailboxes you control.
- Record which folder each provider uses and the message’s authentication results.
- Keep changes controlled when comparing sends. Different routes, content or missing checks cannot prove a fix caused improvement.
Those mailbox observations apply to the tested recipients and time. They still do not guarantee future placement for every recipient.