Emails deleted off phone and server by mistake

Hi,

I had my emails set up on my iphone and also on my partners phone as well. We went overseas and our phones were on roaming. When I returned home all my emails were deleted off my iphone, my partners iphone, the ipad and computer. We both have iphone 5's.

Does anyone know how I can retrieve these? They aren't in the trash and everything seems to have vanished?

Thanks,