postmark
US /ˈpoʊst.mɑːrk/
UK /ˈpoʊst.mɑːrk/

1.
carimbo postal, selo postal
an official mark stamped on a letter or parcel at a post office, indicating the place and date of posting and cancelling the stamp
:
•
The letter had a clear postmark from London.
A carta tinha um carimbo postal claro de Londres.
•
Check the postmark to see when it was sent.
Verifique o carimbo postal para ver quando foi enviado.