Users can download and view attachments that exceed the maximum attachment size setting in mobile device mailbox policy in Exchange Server 2016

Applies to: Exchange Server 2016


Consider the following scenario:
  • You create a mobile device mailbox policy with an attachment size limit of 1MB and assign that policy to a user.
  • You set up an account on an iOS device and send an email message that has a 2MB attachment to that account.
  • You download the attachment from the iOS client.

In this scenario, you can download and view the attachment without an error message.


This issue occurs because the mobile device mailbox policy isn't enforced.


To resolve this issue, install Cumulative Update 11 for Exchange Server 2016 or a later cumulative update for Exchange Server 2016.


Microsoft has confirmed that this is a problem in the Microsoft products that are listed in the "Applies to" section.


Learn about the terminology that Microsoft uses to describe software updates.