I have an AOL account, not through Verizon, and the outgoing server is smtp.aol.com on port 465, SSL/TLS security. This is the same as given here. For the incoming, you should have pop.aol.com on port 995, SSL/TLS. The User Name for each server is the full email address. The authentication is 'normal password', but use an app password if you have 2-step verification on the account.

I got the following error message:

"Sending of password for user green_sky@verizon.net did not succeed. Mail server pop.aol.com responded: [SYS/TEMP] Server error - Please try again later."

Attached are the server settings and the outgoing settings.

Is there anything else you need to help determine the problem?

The settings look OK, and the error from the server doesn't provide much info. Verify the password by logging in through webmail, check if 2-step verif. is on the account, and open Tools/Options/Security/Passwords/Saved Passwords in TB and remove obsolete passwords, if any.

I went through and deleted all the passwords that dealt with the second account, green_sky. Please see attached JPG

Then I exited Thunderbird and invoked it again. I got the following message:

"Sending of password for user green_sky@verizon.net did not succeed. Mail server pop.aol.com responded: [SYS/TEMP] Server error - Please try again later."

I am now completely baffled.

Is there anything else that you can think of?

Do you have to enable POP access for the account in the account's webmail settings? Some providers enable IMAP by default, but POP must be enabled manually. If app passwords aren't an issue, I can't think why the fhd account works but the other doesn't. I've always used IMAP access for my AOL account, and have experienced few if any service interruptions. But with any mail service based on Yahoo (AOL, ATT, Rogers etc.), you don't expect consistent performance.

I looked online at AOL.COM and I do not see a place for enabling POP manually. Please see the attached. Where would this switch be? I opened the OPTIONS tab in the screen shot.

It would normally be under Mail Settings, but I don't see it there, so I guess it's enabled by default. I did notice that after March 2, 2020, the option to enable access by 'less-secure apps' will disappear, which may affect AOL POP accounts accessed in TB. OAuth2 authentication, instead of 'normal password', is supported in TB for AOL IMAP accounts, and OAuth2 is independent of whether 'less-secure' is enabled or not, same with two-step verification.

Is 'less-secure apps' access enabled for the account? Click Account Info under Options, then Account Security.

Account Security has nothing like 'Less-Secure-Apps'.

Double checking. I made sure that each account had exactly the same settings before we made changes. The only differences dealt with account names. Are there any other tabs in the setup for the account that could be causing this?

If both accounts have the same settings in TB except for User Name and password, the only difference would be in the accounts themselves on the provider's site. I've attached a picture showing the Account Security.

Please look at the attached. The 'less-secure apps' does not seem to be there.

I believe that we have exhausted all the alternatives, unless you can suggest something else.

Hmmmm.... Could the problem be that I have let the email stack up for a few years? I mean, the whole point of this exercise was to download all the email that has backed up.

I am asking whether the errors you have seen from me could be generated, because I have such a huge amount of data to download?

Unless you have reached the storage quota, I don't know why you still get the error, or why your security settings don't show the less-secure apps switch. I bet it will work if you add the account to TB as an IMAP account with OAuth2 authentication.

I do not understand what you are suggesting.

Are you saying that I should delete the green_sky account that is not working and start over with some other settings? If so, which ones? I do not see "IMAP and OAuth2 authentication" anywhere.

You can keep the POP account, but before you add the account as IMAP, change the Account Name of the POP account to something other than the email address, e.g. green_skyPOP, in Account Settings. Then, File/New/Existing Mail Account and add it as IMAP with imap.aol.com on port 993, smtp.aol.com on port 465, SSL/TLS, authentication = OAuth2, User Name = email address. Those settings work for my AOL account. If you wish to remove the POP account, first copy any important mail to Local Folders.

Let's try this again. I have nothing on the green_sky account. No mail, nothing. In April of last year I got 'new' computer. The fhd account has always been my primary account. I give the Green_sky account when I suspect the vender I am giving it to, of spam.

Okay. I will delete the green_sky account and implement the changes you suggest. We shall see what happens.

TB will not accept these setting. I do not see a "authentication = OAuth2". What am I doing wrong?

Did you get a message under the remember password checkbox? Something about settings found. If it says settings not found, the problem will be in your anti virus or firewall or some other security software. But the message appears before you click any manual setting dialog. You should not need to do that at all.

When I attempt to add an account I get this.

This should simply work after clicking done. However you do not get that settings found in ISP database message unless your connection to the Thunderbird web server with AOL settings is clear and unblocked by other software.

If you have VISS you might actually need to remove it as McAfee has been causing trouble since December 2012 when McAfee created a new heuristics engine.

Green_Sky said

TB will not accept these setting. I do not see a "authentication = OAuth2". What am I doing wrong?

Go Offline from File/Offline/Work Offline, then File/New/Existing Mail Account, enter your credentials, click Manual Config., and you will see the window in your picture, except the Advanced Config. button is available.

Enter imap.aol.com for the incoming server on port 993, SSL/TLS, smtp.aol.com for the outgoing on port 465, SSL/TLS. User Name is the email address. OAuth2 is not available in the authentication drop-down, which is a bug, so click Advanced Config. and select OAuth2 in Server Settings, same in Outgoing Server (SMTP). After the account settings are entered, close the window and go back online. When you connect to the account, you should see the OAuth browser window appear, where you enter your password and have the oauth:// token stored in Saved Passwords.

Nope. Look at the JPG I sent you. The 'Advanced Config' is grayed out. It will not respond.

One thing confuses me here. Why is my version of TB different from yours? I would expect that updates would make all the versions the same. Just an observation. I do not really care.

I am just confused as to why multiple accounts on AOL is such a hassle. Is this just me, or is this common?

Advanced Config. is greyed out unless you are Offline.

Some pictures: TB 68.4.1/W10. First, File/Offline/Work Offline, then File/New/Existing Mail account, enter credentials, click Manual config., see first picture. Click Advanced Config., see second picture, where all settings can be entered, including OAuth2 authentication.