Attachments Are Corrupt, what can I do?

We just converted to Office 365 and when BB Classic users enter their new information for ActiveSync their email attachments indicate that they are corrupted. They can however send that same email(s) to other recipients from their BB and they recipient can open the attachment without issues. The phone to my knowledge has the newest version of Hub. Is there anything in the settings that I can adjust to get his attachments to open again, also, saving to the phone and opening is not an option for these users.