Hello, ncmtgman.
If you find yourself getting the error “Unable to Verify / User ID or Password Incorrect” from the Mail app, It’s not you. It’s probably because after recent security changes were made there, AOL thinks the Mac Mail app is not secure if it’s from macOS 10.13 or older, and they won’t let Mail connect to their servers– unless you create a special, “app-specific password” and use that– and not your “real” AOL password– in the Mail app..
Even though you know the password for your AOL account– one way to be sure: go to aol.com in a browser and sign in there to prove that you know it– Mail on a Mac will not work with that password if your Mac is on 10.13 or earlier.
The solution: a custom, special “app password,” generated by AOL, just for the Mail program.
Creating an app-specific password is easy, and AOL provides directions. After you create the app-specific password, write it down for safekeeping. Better yet, copy it so you can paste it without making a typo.
Once you’ve received you app specific password from AOL, return to Mail > Preferences > Accounts and input the new password into your account.