Was heisstcustomer advised to pick up mail

I think you meant to ask "Was Heisst customer advised to pick up mail?"

Heisst is a German word that means "is" or "to be". So, if we translate your question, it would be "Was Heisst customer advised to pick up mail?"

To answer your question, I'd need more context. Who is Heisst, and what kind of customer are we talking about? Is Heisst a company, a person, or a fictional character?