I have seen most of the post-marks—and the interiors—upside down.
The letter with the British post-marks on it was placed under his pillow.
Dockwra is credited with being the first to make use of post-marks.
The post-marks, both in Brussels and London, agreed with the date.
Not only telegrams, but letters with no stamps or post-marks!
We all have acquired the habit of looking at one another's post-marks.
The post-marks were illegible, and the envelope much crumpled.
Post-marks now-a-days are very clear, and everybody may know whence a letter comes.
I examined the post-marks of the letters, but they all varied, and were evidently arranged to mislead.
George fingered the letters on his desk, looked at the post-marks, and put them down without opening any.