I've received several similar letters.  One even claimed that they were from a bank in Africa contacting me because they wanted to swindle the bank out of a large sum since no heirs had come forth for one of their clients'  accounts and I was to pose as one and split the money with the bank assistant :)   Naturally they asked for my account number and routing number as StevieG1965  says, to deposit the sum for me.

I'm amazed how they think anyone would believe such a preposterous story!