My mobile users are unable to download large attachments (over 4 mb) on either iOS or Android-based devices. iOS returns an error of "cannot download attachment" or no error at all. Touchdown for Android returns "Exceeds allowed download size"
for an attachment over 10 mb and "internal server error" for attachments over 4 mb.
There appear to be no settings on either class of device that are restricting attachment sizes. Exchange 2010 shows "MaxAttachmentSize" property of all ActiveSync policies is set to "unlimited".
The same users can download and open the same attachments using Outlook or OWA.
Any ideas what I should be looking at?