Sending a thank you email after an interview is such a bad habit we have made during interviewing
After every interview people are expected to send a thank you email.
My company encourages this behaviour. Coz they think that employee has manners or some rubbish. I dont see the point.

What is wrong with sending one sentence "It was pleasant talking to you. Thank you for the opportunity."
I think it's a courtesy to thank the interviewer after the interview. Above that it serves no purpose.
Being courteous can go a long way, since they might refer you for future jobs at the same company, but that's a very rare occurrence if you haven't already got the job in the first attempt.