Clue: Many unopened letters

Answer: SPAM

Length: 4

---

Similar Clues:

• Boxscore letters (RHE with 3 letters)
• SLR letters (ISO with 3 letters)
• Letters on aircraft carriers (USS with 3 letters)
• Designer-label letters (DKNY with 4 letters)
• Introductory letters (ABCD with 4 letters)
• Letters on an invite (RSVP with 4 letters)
• Former call letters? (MCI with 3 letters)
• Letters seen after forward slashes (WWW with 3 letters)
• Job listing letters (e.g. EEO with 3 letters)
• Letters before "Freddie Knuckles" and the like (AKA with 3 letters)