Today when I logged into my email account, it appears that all of my emails and folders have disappeared...

It is like a new email account. I even received a welcome email from outlook.com, however I have had this email for many years (at least 10 years).

There are no emails in the deleted folder and it could not recover any emails.

My documents, calendar items and contacts still appear to be ok.

Could someone pretty please help?? 

I am quite worried.