PASSWORD

Have you tried importing your account setting from desktop to mobile using the QR code method. This transfers your account password and server configuration. See the guide below. https://support.mozilla.org/en-US/kb/thunderbird-android-import#w_how-to-import-from-thunderbird-desktop '''Password''' Is the long password 16 characters in length. If so, it may be an "app password". An app password can be used to setup an account in Thunderbird Android. Most email providers no longer allow email clients to authenticate using an account holders normal password. They prefer more modern secure authentication such as oAuth. As a less secure alternative, they allow users to generate a 16 character "App password" using their web-mail settings page. This is entered in the email client instead of a users normal account password. You can read more about app passwords in the link below. https://www.historytools.org/docs/what-is-an-app-password-and-when-do-you-need-one-instead-of-your-normal-sign-in If you require but don't remember your normal account password, most email providers have a password reset button on their webmail sign-in page.