I use Mozilla Thunderbird as an 'app' on my PC (Windows 10) in order to access my Virgin Media mail - @ntlworld.com. In the last fortnight my outgoing e-mails have not been sent, and a message 'Sending of the message failed. An error occurred while sending mail. Authentication Required (VM401)'. After much time searching for solutions on the internet, I understand that it was because Virgin Media now require a two stage authentication, and I would need to generate a new password specifically for e-mail apps like Thunderbird. After a great deal of grief, I eventually believe I have now generated this 'app password', but do not know how I can update Thunderbird (if that is what is required?) to include this password. I have updated the SMTP settings, but there appears to be nowhere to include this password. I would be grateful if you could cast some light on this problem. Regards, Stephen Hartley.