Related Clues:

• Pt. of SASE (Abbr.)
• An SASE is one
• Stationery item, briefly
• Env. in an env., say
• Env. insert
• Part of S.A.S.E.: Abbr.
• Letter-bottom letters
• Env. inside an env., e.g.
• It's in an env.
• Ref. wd.
• Something sent with a ltr.
• Env. attachment
• Check, perhaps: Abbr.
• It's added to an env.
• Unsolicited MS., perhaps