all of my emails from my inbox disappeared over night. I want to get them back how can I do this ?

A few days ago I noticed the all of my hotmail messages that were on my iPhone were gone. I didn't think anything of it until I checked my emails on my laptop and saw that all of my emails in my inbox were gone. I did not place my emails into any folders thinking they would be fine left in my inbox. However, now I am left with none of my emails that I had in my inbox. I had many emails left there that I need to access now and they are just gone. I need this problem fixed as soon as possible. This is unacceptable.