Too bad this support site doesn't provide a way to preview your post before submitting nor a way to edit your post after submitting.

Should be "Clearly, this is *not* done"

Too bad this support site doesn't provide a way to ... edit your post after submitting.

It does. There is a 'Edit this post' link to the right of your post.

Wrt the "Not Responding" issue, what is your anti-virus software?

I'm typing a reply to an e-mail. In the middle of typing a word, TB freezes and shows "Not Responding" in the title bar. This goes on for maybe 20 seconds and then all of a sudden, the text I typed appears. Why on earth would the TB UI stopping responding while typing an e-mail. This should not require any interaction with a server. At most, maybe it is autosaving? This seems like a fundamental architectural issue with TB. Modern software design decouples the UI from background processing. Clearly, this is done well enough with TB since it is constantly "not responding" and is very susceptible to any issues in profiles, mailboxes, etc. No other software I have ever used has been this problematic on this front, including a lot of Microsoft crapware.

Just started in the last few weeks.

I am having the same problem with Thunderbird 68.7.0 It will freeze while I am typing, then start to fill in what letters I have already entered in a very slow, one by one manner. Also I will click on a message to open it and Thunderbird will open the last mail I read and then freeze for quite a few moments and finally open the one I clicked on. The screen will occasionally go completely white with all text grayed out. I keep my folders compacted, I only keep around 3 months of important mail on file.

My antivirus is Windows Defender on Windows 10 Pro, 16gb RAM, 3.4Ghz processor

wrgarrett45,

please start a new topic for your problem. https://support.mozilla.org/questions/new