Yes… this takes extra effort as you need an extremely accurate list with first names. But I have always found it worth the pain... and the sales people like the email continuity with their follow-up. It is especially nice when prospects reply in the first person!
Two details: create a faux email address (that is still your real name) for the replies – otherwise, your “regular” email will be bombarded with “out-of-the-office” alerts. Also, put a few breaks between your signature and the spam compliant text. Hiding this text aids the illusion. (aww c’mon. this IS marketing)