Doesn't "thanks" imply a request was made, and "best" imply the end of a conversation? Did they just analyze a bunch of emails blind?
- got your fire drill and I'm handling it... Cheers (don't worry about it)
- won your business, thank you so much... Cheers (celebrate)
- scheduled a meeting for next week. looking forward to talking to you... Cheers
To say thanks after everything seems odd to me. Kind of means nothing in many contexts.
Cheers at least reinforces your tone and personality (assuming that's how you are) in really any context and how you conduct business.
I still use thanks of course to be thankful, but almost always close with Cheers.
https://blog.boomerangapp.com/2017/01/how-to-end-an-email-em...