Are we still sending obligatory "thank you" emails? I find it cheesy and trite by maybe that's the just me. I only send it to a program that I truly really liked and want to go to as my first choice, but in addition to thank you I add some more substance explaining the fit (without droning on too much). Otherwise for other programs, its honestly part of the job to interview applicants. Don't get me wrong, when I was a 4th yr med student applying for residency, I did because "I was told to do so" but at this level there is more maturity in the process and less of a "take me take me" and more of a mutual discussion to see if there's a good fit. But basically if there's nothing of substance to ask the individual (like an honest question or something) I'm not sure the point of the thank you other than filling inboxes. But to each their own I suppose. Gluck friends 🙂