I do not accept that my old e-mail is totally lost. Can anybody help ?

Before could I connect to all my e-mail with this string : https://mail.opera.com/mail/Inbox/
The string is not working any more and all I get is: http://www.opera.com/no/whereismyopera
I have a lot off older email's in different folders saved in my email archive. I wonder how I can access these folders. Please answer A.S.A.P. as some of the email's are important to me.
Regards
Sigurd Bjørn Kastrud
sibjo-k@online.no