Hello @Abdul_Ahad,
From your post, not sure what exactly to check.
The folder exists, because it was working for few times, but after that it’s crashing at the Get Outlook email, with one of the messages from above. (folder not found or Outlook not having resources).
Only a server reboot resolve it, but for a short while.
After searching a lot on web and trying out different solutions, I was finally able to fix this.
I had a 24*7 email monitoring bot where in this issue will come up a few hours of bot deployment.
A simple outlook setting change could fix this.
Here are my steps to fix this.
Go to Account settings in outlook through File Tab on top left.
Open Data Files Tab → Settings and advanced and then just uncheck the, use cached exchange mode option.
You may find the screenshot depicting this settings change here.
Please do share if this works for you too.