Office 365 sites can be redirected, but the method is a bit unconventional.
Add a PayPal module to the Office 365 site and replace the code between the <form> tags with the redirect script that we provide in the editor under step 4. This should result in something that resembles this:
<form action=""><input type="image" style="display:none;" />
Just replace INSERT_MOBILE_URL_HERE with your mobile url (keep the quotation marks). Once that's been placed in your site (ideally near the top of the page) your site should redirect properly.
Note: This redirect method will need to be used on all pages which you want to make mobile friendly.