It has taken some months to happen but the Sky Broadband SMTP mail service has been turned off this week. The result of this is that if people have not updated the settings for their email software they will not be able to send emails.
The Register quotes one reader who reckons a lot of people will get caught out and not have altered their software. So far we have not come across any posters on our forums desperately seeking help, but just in case you can download the official Sky documentation for the changes. The main change to the SMTP server settings is that you should now use smtp.tools.sky.com rather than smtp.sky.com, the TCP port used by the server is 465 rather than the standard port 25 and finally you need to enable SSL authentication in your mail client.