OSX mail unable to verify account name or password

Creating a new account in Mail on OSX Big Sur (11.2) and complete the required information for:

• Email
• Username
• Password
• Account type: IMAP
• Incoming mail server
• Outgoing mail server

I receive a message "Unable to verify account name or password."

Note: before you follow these steps, ensure that you know / note down all of your account passwords.  This is because the saved passwords will be deleted during this process.

The steps that worked for me:

1. Open the Keychain Access utility in your Applications folder
2. In the Keychain Access dropdown list, open Preferences...
3. Click Reset My Default Keychains and follow the prompts
4. Restart your computer

You will be prompted to re-enter the passwords for all your e-mail accounts. If you were having trouble adding a new e-mail account, it should work fine now.