carry the mail (for someone)

To work assiduously, especially in a central role of some difficult or demanding task. Primarily heard in US, South Africa. With their captain out with an injury, it's up to their young star player to carry the mail for the team in this game. The boss carried the mail himself to make sure this project was completed on time.

Common Names:

Name	Pronounced	Usage
Hermenegild	her-ME-ne-gilt	German
Alayna	ə-LAYN-ə	English (Modern)
Rasmus	RAHS-moos	Danish, Swedish, Norwegian
Simonides	-	Ancient Greek
Karpos	-	Ancient Greek, Biblical Greek
Juli	YOO-lee	Hungarian