How did you change the sorting? By clicking the little buttons at the top, or via the menu? If you didn't use the menu try it now. View|Sort by...

I tried the top button, the menu, re-starting the computer, clicking the choice to allow the script to continue and finally after a few hours it was released and everything works now. Thank you for your suggestion.

My t'bird froze after sorting by "correspondent," and it did not respond to the menu "view--> sort by command" . In fact, it doesn't respond to any commands. The underlying problem is probably that it seems to have been retrieving verizon.net mail (from AOL) too frequently; it now has 20+ copies of some emails, and about 90,000 total. (I had it on AOL's POP3 settings, which worked fine until a few weeks ago.) AOL says to go to "tools-->account settings" and delete and re-add the verizon account. I cannot go to "tools-->account settings". Is there a remedy within my existing T'bird? If not can I delete the program and reinstall another from the Mozilla website - - without losing my verizon.net email account?

Thanks you please start your own thread. This one is different from yours, 1 month old and solved.