Well firstly the link you send me asks me to log in via my"My Virgin Media" page and that uses a @virginmedia.com email address and works fine on all browsers except Google where it doesn't work at all .
When I log in to My Virgin media and go to the Webmail page I see my main email inbox at the top, then a gmail box with nothing in it (no idea why that is there) and at the bottom is my 2nd @virginmedia.com email address mailbox . I do not see any mailbox related to my blueyonder email address
If I go to Settings, there are only the 2 @virginmedia.com emails listed no blueyonder email