Answer:

mail

Answer	Crossword Clue
MAIL	Daily delivery
MAIL	It may be junk
MAIL	It may be electronic

MAIL	Weekday delivery
MAIL	It's often junk
MAIL	Knight wear
MAIL	Bills, etc.
MAIL	Flexible armor
MAIL	It's in the bag
MAIL	Outdoor box contents
MAIL	Four letters?

MAIL	Correspondence
MAIL	Knightwear?
MAIL	Cubbyhole contents, maybe
MAIL	Vacation cancellation
MAIL	Reader responses, possibly
MAIL	Relatively lightweight armor
MAIL	Vacationer's accumulation, perhaps
MAIL	E follower

MAIL	Snail follower?
MAIL	It might be registered
MAIL	Send
MAIL	Post office delivery
MAIL	Kind of bag or box
MAIL	Letters in a box
MAIL	"You've got .."
MAIL	E or G follower

MAIL	Post office sackful
MAIL	Postal delivery
MAIL	Knight's protection
MAIL	Postal sackful
MAIL	User's morning reading
MAIL	Junk ..
MAIL	Post
MAIL	It may be registered or certified

MAIL	Word with fan or snail
MAIL	Knight dress?
MAIL	Snail ... (slow post)
MAIL	"The check's in the ..."
MAIL	Letters