I have two ntlworld.com email accounts and I use Thunderbird email client. As of this morning, I haven't been able to receive any emails from either of my accounts, both are coming back with the message "Sending of password for user ********@ntlworld.com did not succeed. Mail server pop.ntlworld.com responded: [AUTH] Authentication failed". I've also tried logging in to my Virgin webmail and this is failing also. Is there a known problem or explanation of what could be happening please?