Ipad mail transfer

As I have finally changed my Ipad with the new one I also need to transfer all the data to the new one esspecially my e mail messages. As that is imposibile to do vi cloud or iTunes back up (tried to many times) I was wandering if anyone has an idea or experince with this? THis is crucial for me as without this posibility I cannot switch to the new one as these mails are required for my work. Please let me know if there is a solution or some app for this. Thx...