If you use the newer versions of Outlook it has some inane one-shot reply buttons you can click that is based on the content of the previous email and presumably some model built on you.

My work computer uses Outlook, and it usually has options like these

• Gotcha, thanks
• Brill, thank you
• I will do that, thanks

At my old workplace though, one of our customers would always respond with a couple of letters. Could be something like

Customer:
Hi. Could you update thing on website?

Us:
Hello!
Absolutely. We’ve rolled out the update, and you should be able to see it now.
Hope all is well over there. :)

Customer:
T M

Where T is short for “Thank you” and M is short for “Mary”

Ah. They were fantastic. Frustrating but awesome people.