Attachments on meetings or appointments are not available when you synchronize the Calendar with an Exchange ActiveSync client.
This problem occurs if one or both of the following conditions are true:
- The Exchange ActiveSync client doesn't support version 16 or a later version of the Exchange ActiveSync protocol.
- The mailbox is located on a version of Exchange that doesn't support version 16 or a later version of the Exchange ActiveSync protocol.
To synchronize attachments in a calendar item, follow these steps:
- Move the mailbox to Exchange Online or to Exchange 2016.
- Upgrade the device to a client that supports version 16 or later.