if you lok carefully at the addresses you will find the the "From" address is meaningless (I am told) it is just text. The reply address is very revealing, they open an account at gmail or live.co.uk (etc) with the same personal name. In replying you see the persons name (or soubriquet) and don't register the altered domain.

Another scam coming along is the "perfect job for you"
My recent instance came to an address I never use for jobs, the jobs one was always job@ or jobs@ (for jobsites). Given that I am an electronic engineer they sent a job spec for financial controller (no experience necessary) and I was perfect for the role!
I replied by using an e-mail address that looked like the name it came in on- asking them to pay a release bond and could they give me all their account details. I haven't heard from them.