postalgame
nounUK /ˈpəʊstəlɡeɪm/
US /ˈpoʊstəlɡeɪm/
A game you play by sending letters or cards through the mail.
We started a postalgame with our cousins in another city.
OTHER MEANINGS
2. A playful contest where players mail moves or clues to each other.
The chess club ran a postalgame across three towns.
3. A game involving pretend postal delivery for kids.
The children set up a postalgame with toy mailboxes.
4. Any activity or challenge carried out through postal correspondence.
Their postalgame of riddles lasted all summer.