User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:87.0) Gecko/20100101 Firefox/87.0
Steps to reproduce:
I have a problem with your "automatic" decision to compress the email folder as the S/W is written evaluate the coded threshold and finds it necessary to ask. When I am going through my email, and delete a mail, the S/W sometimes decides to "ask" if you want to compress the folder. Having terabytes available for my email, I don't want to do this. I clean my email myself.
The problem arises when the "suggestion" to compress displays down at the bottom half of the screen. If it comes up just as you are selecting the next email to read, your cursor has been placed in the "yes" box of the question. This happens more than you can imagine.
Now that the process is selected, whatever the programmer is doing COMPLETELY bogs down the system for a VERY long time. You can't do ANYTHING on the system (start a browser, even look what's going on through task manager etc.).
I would like to suggest you NOT place the cursor into the box when asking this question and "lock" the process until you move to the box area to select yes or no. To many times you are hitting the mouse to select another email to look at. Then the system "freezes" for a VERY long time.
P.S. I have to add, I have been using Thunderbird for a LONG time and find it a FANTASTIC tool to manage my emails. Thank you for an excellent product.