First of all do not answer back, otherwise they will know your email is a valid one (usually they try several emails from list sold in the black market).

Second do not call (some people are so naive that they call and then they are forced to perform some tasks for the scammers to have the person personal Info); if you call then you have been caught. And believe me you do not want this to happen.

Third DO NOT DISCLOSE ANY PERSONAL INFO to anybody on email or you will become a fraud objective.

And last but not least, simply erase the message, and if by any chance it asks for read receipt simply say no read receipt.

Best regards!!!!!