Husps hold mail
I think you meant to say "husks hold mail".
Husks are actually the dry, outer shells of corn kernels, but I'm assuming you're referring to a different context.
In the context of mail delivery, a "mail husp" or "mail box" is a container or receptacle used to hold mail and other postal items. It's typically installed at a residence or business to receive mail and packages from the postal service.
Is that what you were thinking of?