I believe AOL requires a separate APP password for email clients, not the one used online. Check your AOL account page and click the security link for more information.

Thank you so very much for your prompt response! I can't find anything that seems to apply in the security settings, tho I'm not an AOL expert. It's been working just fine for a long time and I'm loath to start making changes. The OAuth2 switch was a real pain to put it mildly. Using my laptop, iphone etc. needing the same password and security and so on. Thunderbird's message is: "The server does not support the selected authentication method. Please change the 'Authentication method' in the 'Account Settings | Server settings'." AOL/Compuserve might have changed something, I just don't know. Any suggestions? Thanks, Sheila

As I mentioned, AOL is not something I know well. I did find this site about APP passwords: https://help.aol.com/articles/Create-and-manage-app-password And you might post a screenshot of your smtp server settings and someone here may have further suggestions.

What is the incoming server for the Compuserve account? If it's not imap.aol.com or pop.aol.com, OAuth2 won't work, and you'll have to create an app password on the AOL/Compuserve site. The Yahoo account with imap.mail.yahoo.com or pop.mail.yahoo.com will work with OAuth2.

Server setting: pop.aol.com port 995 I'm still at a loss... Sheila

The correct settings are: pop.aol.com on 995, SSL/TLS, OAuth2 authentication, User Name = email address; smtp.aol.com on 465, SSL/TLS, OAuth2 authentication, User Name = email address. Remove the passwords and oauth entries for the account from Saved Passwords in Settings/Privacy & Security, restart TB, enter the account (not app) password in the OAuth window to allow TB access. Allow cookies in TB Privacy & Security.

I tried various combinations and the result is that it appears that whatever handshake is going on between TB and AOL/Compuserve, the O2Auth2 portion is not getting generated, either TB not sending the right data or AOL/Compuserve not responding. Again, I have two mail accounts on TB, both use OAuth2, one (Yahoo) works and the other (AOL/Compuserve) does not. I verified everything that you mentioned, and deleted the both passwords, then re-entered the AOL/Compuserve when asked.

Do you have an app like Avast or AVG scanning outgoing mail? If so, disable that option in the app's settings (e.g. 'Mail Shield'), as they often interfere with secure (SSL) connections. It often happens that when mail connections fail after a TB update, it's because the antivirus becomes incompatible with the new version.

I think you might be seeing this bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1782250

i.e. OAuth2 fails for AOL POP when the email is not @aol.com, such as @verizon.net or @compuserve.com.

See if it works in the latest update 102.1.1, which includes this fix:

"OAuth2 authentication was not available when the mail domain did not match the OAuth provider domain"

Did the upgrade. Results: After upgrading to TB 102.1.1 with NO password for AOL/Compuserve And OAuth2 selected, as soon as “get messages” is selected, INSTANT reply of “The server does not support the selected authentication method. Please change the 'Authentication method' in the 'Account Settings | Server settings'.”

With “normal password” Sending of password for user 73157.2714@compuserve.com did not succeed. Mail server pop.aol.com responded: [SYS/TEMP] Server error - Please try again later. Added password Login to server pop.aol.com with username 73157.2714@compuserve.com failed. Selected OAuth2 The server does not support the selected authentication method. Please change the 'Authentication method' in the 'Account Settings | Server settings'. Thank you so very much for your continued effort! Sheila

Just to clarify: with *.aol.com servers, the authentication should be OAuth2 with the account password entered in the OAuth window, or, authentication as 'Normal password' with an app password.

I don't know if this is an AOL issue or a bug in TB. Consider adding the account as IMAP (you can't switch between POP and IMAP by just changing the settings). I have an @aim.com account working fine on imap.aol.com.

Just what would this "you can't switch between POP and IMAP by just changing the settings" entail? As time goes by, my emails are diverging and at some point it will no longer be possible to continue trying to use TB for one account and the other via FF. My brain is getting fried. I've had a fascination with electronics from crystal sets to tubes to chips, making my own board, some programing, networking, main frames a bit and Military systems; I still build my own computers at 76. And still this geek girl is feeling like a dummy. Something has changed, but what I have no idea... Ideas to pinpoint? Thanks, Sheila

Sfhowes is just reminding that an account cannot be changed to/from POP or IMAP. If you want an IMAP account, it must be separately defined. If you want both POP and IMAP for the same account, that is not a problem.

I attempted to add a IMAP account to my compuserve account, but it hung at the AOL end, I assume, with something about authorization with a long string of letters/numbers.

Please post your results using 102.1.1 and the pop account.

AOL requires an APP password, not the same one used online. You will need to sign in at AOL and select the security link to do that.

I'm not sure where this is going, but Wayne Mery asked, so I'm posting again. After upgrading to TB 102.1.1 with NO password for AOL/Compuserve And OAuth2 selected, as soon as “get messages” is selected, instant reply of “The server does not support the selected authentication method. Please change the 'Authentication method' in the 'Account Settings | Server settings'.”

With “normal password” Sending of password for user 73157.2714@compuserve.com did not succeed. Mail server pop.aol.com responded: [SYS/TEMP] Server error - Please try again later. Added password Login to server pop.aol.com with username 73157.2714@compuserve.com failed. Selected OAuth2 The server does not support the selected authentication method. Please change the 'Authentication method' in the 'Account Settings | Server settings'.

This is what it mentions: App Password If you don’t normally use a password to sign in to your AOL account, here’s where you can generate a password for 3rd-party apps that require passwords.

I've never needed one before, but if it generates one or whatever, where would it be entered in TB? I've used Thunderbird for most of it's existence, and my compuserve account is older than most people; this is the first time I've had a serious, very serious problem. BTW, my outgoing server is smpt.aol.com

You apply the app password in TB in the same place you would apply the normal account password. Remove all entries for the account, incoming and outgoing, in Saved Passwords, check that the outgoing server is smtp.aol.com (not smpt.aol.com) with 'normal password' authentication, restart TB, enter the app password when prompted for a password.