Related Clues:

• It may go in a lock
• Ocean liner, for one
• ---
• Treo button
• Drop in a mailbox
• Start of a Sondheim song
• Send in a crate
• FedEx
• Mail away
• Scow or skiff
• Ship or mail
• Text messaging command
• Salt container?
• Drop in the mailbox
• Excite, in slang