This is the classic 419 Nigerian Scam
I would forward copies to the ISPs from the e-mail
So send it to abuse @ hknetmail . com
Also check where the e-mail came from as they now tend to send from one account but want answers sent to another one. Send to that abiuse @ ISP . com address to.
Then just delete it. You can't stop it arriving any more than you can stop someone sending a letter.