I used to work with someone who might fairly be described as curmudgeonly.
This person detests people who reply to an e-mail with a one-word Thanks.
Needless replies are a bit annoying, but it’s also hard to know when to terminate an e-mail exchange.
The advice I give to law students in my seminar on e-mail in a professional setting is to err on the side of politeness, especially in relation to more senior peeps.
Even at the risk of irritating a curmudgeon.