email lost and body unrelated to email subject/sender

My wife's iPad running iOS 7.1.2. On our email service she created a folder called "keep", to store emails that were very important to her.

Of course now we have a major failure. Her "keep" folder was emptied somehow of all but a few messages -- and those messages are mangled. The body of the message has nothing to do with the subject/sender. For example, there will be an email with her brother's name as the sender -- but the body of the email is content from someone else totally outside the conversation.

So two basic problems - first the 'keep' folder was somehow partially deleted both on the iPad and on the host email account (optonline.net, which is our ISP).

Second, the emails that remain are mangled. That is only on the iPad -- the host account is fine.

I don't expect anyone to figure out how or why the emails were deleted but I do need to come up with a solution for her so her important emails don't get lost or mangled anymore.

Questions:

- Should I just delete the entire email configuration from the iPad and then re-instantiate it?

- Is there some sort of "rebuild" feature I can use, to re-synch all the folders from the server to the iPad (but NOT cause the corrupt information from the iPad to be synched back to the server)?

- Any other pointers would be appreciated...we no longer trust the iPad and she is telling me to get rid of it, which I don't want to do just yet.