I am using Thunderbird (v102.14.0 - 32 bit) on Windows 10. It regularly freezes up (like every few minutes) while some background process is working. In Windows task manager during these lockups I see that Thunderbird is consuming a large percentage of machine resources and using over a gigabyte of memory (but no disk activity). After a minute or two, it apparently gets done with whatever background process it is doing, and everything is normal again. For what it's worth, I notice that when this happens other mozilla apps like Open Office Writer and Open Office Calc are also locked up. So whatever is going on it must be part of the common kernel used by Thunderbird and these other apps. This behavior just seemed to begin recently (last several months), and it makes trying to use Thunderbird and writing emails very frustrating and time-consuming. Whatever background process that is executing needs to be changed so that it is a non-blocking thread so the rest of the program functionality still works while it is executing.