On my Thunderbird email I receive an error when sending an email that says: Sending of the message failed. An error occurred while sending mail. The mail server responded:<[email protected]> sender rejected. The email address you are sending as must match the email address you used to Auth. Please check your SMTP settings. AUP#Out-1500. Please verify that your email address is correct in your account settings and try again. I checked and the email address is correct. Any assistance would be appreciated. Thank you.