Mail from must equal authorized user?

FLASKY_MAIL_SENDER is Flasky Admin <[email protected]> in project. If i use my email address, then throw a exception like

smtplib.SMTPSenderRefused: (553, b'Mail from must equal authorized user', '=?utf-8?q?Flasky_Admin?= <[email protected]>')

a simple advice, set FLASKY_MAIL_SENDER like

FLASKY_MAIL_SENDER = os.environ.get('FLASKY_MAIL_SENDER', 'Flasky Admin [email protected]')