Postmark (noun)

A postal marking stamped on a letter or package indicating the date and place of mailing.

Origin:

From post + mark.

Examples:

1. The postmark on the envelope showed that it was sent from Paris.
2. The postmark indicated that the letter had been mailed over a week ago.
3. The postmark was smudged, making it difficult to read the date and location.
4. Collectors value antique postmarks as they provide a unique insight into postal history.
5. The postmark on the package was used as evidence of when it was sent in court.