Answer:

env

Answer	Crossword Clue
ENV	Part of SASE
ENV	Stationery item: Abbr.
ENV	No. 10, for one

ENV	Ltr. container
ENV	Ltr. carrier
ENV	Letter carrier: Abbr.
ENV	It may have a window: Abbr.
ENV	It may be self-sealing: Abbr.
ENV	Ltr. holder
ENV	Part of SASE: Abbr.
ENV	Pay holder: Abbr.

ENV	Bill holder: Abbr.
ENV	It needs to be addressed: Abbr.
ENV	P.O. purchase
ENV	Part of SASE (abbr.)
ENV	Pt. of SASE
ENV	Ltr. enclosure
ENV	Last pt. of SASE
ENV	It may have a window (abbr.)

ENV	Encl. with a submission
ENV	It encloses a ltr.
ENV	Letter holder (abbr.)
ENV	USPS carrier
ENV	Item opened at the Oscars (abbr.)
ENV	Item in a P.O. box
ENV	The E in SASE
ENV	SASE, e.g.

ENV	Letter holder: Abbr.
ENV	SASE component
ENV	SASE part
ENV	Card holder: Abbr.
ENV	PO delivery
ENV	Stationer's piece: abbr.
ENV	Greeting-card holder: Abbr.
ENV	It might be SWAK

ENV	Wrapper: Abbr.
ENV	Office item: Abbr.
ENV	Paper container: Abbr.
ENV	Stationer's abbreviation.
ENV	Office necessity: Abbr.