Both Snail Mail & E-mail a Good Follow-Up Strategy?

Dear Experts, So I interviewed for my dream job on Monday. Tuesday morning I put two thank you notes in the mail (snail mail) to the two people who interviewed me from the department I'd be working in. Today (Thursday) I got an e-mail from someone in HR following up to see if I have any questions and to give me the e-mail addresses of the two people. Should I send them an e-mail in addition to the hand written thank you note? I don't want to be pushy or invasive but I REALLY want this job. And if I were to send an e-mail, what else would I say? Also, if I don't have any questions, is any type of response necessary to the HR lady? Our Twitter Advice Project (T.A.P.) is no longer an active campaign. To find an answer to the above question, please use the "Search" box in the right-hand column of this website.