After 1.5 hours of my life I won't get back, and excellent help from Level 2 AOL technician, I can once again use Thunderbird (on Win 10) and Aquamail (on Android) to get at the email I pay Verizon every month to use.
But the messaging and documentation around this are pathetic. Last spring AOL threatened to block access sometime in June if customers didn't follow their instructions (https://help.aol.com/articles/allow-apps-that-use-less-secure-sign-in#others). June came and went, boy who cries wolf. Then 11/7/21 another dire warning which this time I followed, using AOL instructions simply to delete my account inside Thunderbird and create it again. The new deadline of 12/7/21 came and went; email still worked. All clear, right?
NO. 1/6/22 access blocked from both my clients. Level 1 tech totally unable to help. Level 2 tech told me to generate an app password (https://help.aol.com/articles/Create-and-manage-app-password) and then provide that 16-character password in my email clients, both for POP3 and SMTP (see Thunderbird screenshot below). This did the trick. Woo-hoo. Heaven help the less computer savvy.
BUT AOL management demonstrated either incompetence or regarding us as pond-scum, by apparently not making that step at all clear. This leaves a clear bad taste in my mouth both for AOL and Verizon.
BTW tick the checkbox so you're not always prompted in future.
