I have just posted this same question on the Spanish forum but I'm concerned that this will be faster. 

My problem is that since one month ago, every single time I open my mail online an automatic folder is been created named as "trash" and it has two mails but when I can open it, it's empty.

On the other hand, my sent mails folder is full of mails cause outlook duplicates them, not once but nearly a thousand times each so I'm not able to empty the folder or keep my new sent mails.

This is really annoying me and I'm considering to delete my account in outlook, so please help me.

Cheers.