Related Clues:
- Envelope routing abbr
- Memo inits
- Abbr. before a recipient's name
- Envelope-directing abbr
- Mail abbreviation
- Abbreviation on a memo
- 25 Across, for one: Abbr
- Subj. line heading
- Something extra in an envelope: Abbr
- RSVP card, for example
- Enclosed, abbr
- Business ltr. insert
- Abbr. before an addressee
- Memo header abbr