theres no date on this page (and their web pages seem to be real sluggish to display for me due to their design) so it's not clear how recent this info is, but read it , they are going to get everyone on a
you@virginmedia.com eventually.
http://www.virginmedia.com/help/virginemail.php
in the meantime does webmail work for you at least?
http://www.virginmedia.com/help/emai.../error-550.php
"This error is telling you that
the problem is with your mail server, not Outlook Express.
It usually happens if you’ve just joined us and you used to access a different email account through your Outlook Express, or if you currently access a few different email accounts through Outlook Express...."
in your case, try typing a simple
telnet smtp.blueyonder.co.uk 25 in a cmd shell and see what response you get.