I recently interviewed at a school that said that they "encouraged" thank you letters. Neither of my interviewers provided me with their email at the end of my interviews, but I was able to find their emails after looking them up online. Would it be appropriate for me to send a thank you letter in this case, or is that weird? So far, I have only submitted thank you notes to interviewers if they specifically gave me their email at the end of the interview, or if the admissions office provided me with their emails.