When I attempt to rapidly delete a sequence of emails in Thunderbird that have arrived in the Inbox using the Delete button on the keyboard, Thunderbird freezes for about 5 full seconds for about 1 out of every 4 emails. The other 3/4 delete immediately.
I also use Nostalgy to allow me to move emails from the Inbox to another folder with the press of a single key, and the exact same problem occurs in that case.
I have run Thunderbird in Safe mode, and disabled my Avast antivirus program's "real-time shields" (including mail shield), and neither has fixed the problem.
Also, I quit Thunderbird & deleted all .msf files, and it did not resolve the problem. I attempted to compact my folders, but absolutely nothing happens when I right-click a folder and select "Compact".
Please note that I regularly synchronize the entire Thunderbird folder to online storage and to other workstations, but I never run Thunderbird simultaneously from multiple workstations.
Please help! This problem is becoming so much of a nuisance that I am seriously investigating other email clients. Thank anyone in advance for any suggestions.