all emails were disappeared from my hotmail account

Hi naoyohs,

Welcome to the Apple Support Communities! I'm sorry to hear that you are having these issues with your email. I'm a bit unclear on the exact nature and scope of the issue you are describing (for example, if the emails are also missing if you access your Hotmail account via the web), but if you are having issues with Mail on your MacBook Air, you may find the troubleshooting steps outlined in the following article helpful (the article is aimed at sending and receiving mail, but also applies in cases where you may not be seeing your mail at all):

If you can’t send or receive email on your Mac - Apple Support

Regards

Hey, did you manage to get our emails back? I'm having the same problem - all of my hotmail (outlook) emails have disappeared and i even tried logging in from a PC. I think something went wrong from my iphone 6s but I just can't understand how like 5 years of emails could disappear like this!