I cannot sync my messages from hotmail to my iphone 5 all of a sudden

I have been using hotmail on my iPhone 5 since last December, it stops synchronizing my emails since 13th August for no reason.

After several tries to delete and add my account, 20 emails from last December came up but nothing more.

I also tried to sync my mails on my friend's iPhone but I still can't get it. I believe there is something wrong with my hotmail account.

Can someone please help me urgently?

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