don't know thunderbird email address to sign in on phone

Please see the guide linked below that explains how to import your email account details from Thunderbird desktop to the android app. The desktop app will generate a QR code that you scan using the mobile app. https://support.mozilla.org/en-US/kb/thunderbird-android-import#w_how-to-import-from-thunderbird-desktop This will usually import your email address, password and server configuration. If your account is using oAuth 2.0 authentication rather than normal password, you may still need to complete your account providers sign-in steps within the mobile app. A quick way to get your email address in Thunderbird desktop: * Click Write to compose a new email. * Look at the From field. Your email address should appear there. If Thunderbird desktop uses password authentication to connect to your email providers server, you should find it stored in the password manager. See the below guide. https://support.mozilla.org/en-US/kb/password-manager-remember-delete-change-tb Thunderbird doesn't store your email account password when oauth 2.0 authentication is being used.