thunderbird mail error

There was an error sending your message: Failed to add recipient:   [SMTP: Invalid response code received
from server (code: 503, response: This mail server requires authentication when attempting to send to a non-local e-mail address. Please check your mail client settings or contact your administrator to verify that the
domain or address is defined for this server.)]

  host   said: 551    This mail server requires authentication before sending mail from a locally   hosted domain. Please reconfigure your mail client to authenticate before   sending mail. (in reply to MAIL
FROM command)