Paste the raw headers and find out.Authentication results, the route it took, and where the delay was. Nothing is uploaded — the parsing happens in this tab.
01 · Authentication
Did it prove who it was?
Read from the receiving server's own verdict, not guessed from the record.
02 · Message
Where it came from
The addresses that matter, including the ones recipients never see.
03 · Delivery path
The route it took
Oldest hop first. Anything over a minute is worth a look.