I have two email accounts name@btinternet.com and I cannot send emails from either. I get the following message pop up: ****************************** Sending of the message failed. An error occurred while sending mail. The mail server responded: authentication required - Your email could not be sent. To fix this you must make a simple change to your email client (known as SMTP authentication). For advice visit http://www.bt.com/smtp. Please verify that your email address is correct in your account settings and try again. ****************************** I have checked the SMTP settings with the details on the BT website (username for the main account, server name, port number, security and authentication) but nothing changes.