Answer: pilesup

AnswerCrossword Clue
PILESUP

Accumulates

PILESUP

Amasses

PILESUP

Saves

PILESUP
More than fills the inbox
PILESUP
Accumulates.
PILESUPAmasses.
PILESUPGrows
PILESUPAmasses, as debt
PILESUPMakes a stack