Enter a clue or pattern or both:
The ClueA ham, sometimes (6 letter answer)
NotesThe answer SENDER is seen occasionally, appearing about once every 900 puzzles.
"Return to ___"
One making dispatches
One going to the post office
Return address info
DefinitionSENDER as a noun:
1. (sender, transmitter) = someone who transmits a message; "return to sender"
2. (transmitter, sender) = set used to broadcast radio or tv signals