Issue
You're not able to see more than 30 days worth of e-mails on your iPad or iPhone.
Solution
In order to preserve system resources, your device is set up with a 30 day cutoff on e-mails. If you need to view more than 30 days worth of e-mails, you'll need to login to the Microsoft Office 365 portal. You can do so here:
Your username will be your [email protected] e-maill address.
Your password will be your e-mail password.
If you require any of the above information, please e-mail [email protected]