There is a department in our company, where the manager and all employees in it permanently have their out of office automated email replies on.
It says "Thank you for your email. I will respond as soon as possible."
Every single day. If you email one of them, you get that completely useless message. And it drives me INSANE. Especially when I have to send a message to the entire company and get flooded with 25 automated replies.
"Oh but we want our customers to know we got their email!" You do you, then, and it's still stupid, but at least set it so it only goes to external emails.