You can also restrict mailbox access by using the Set-CASMailbox cmdlet. For example, to disable POP3 access, run the following command:
Set-CASMailbox email@example.com -PopEnabled $false
The customer can restore any intended custom mailbox protocol settings 48 hours after the new provisioning code is set and after the mailbox is successfully processed by the system. This is because custom mailbox settings can be maintained if the mailbox provisioning code does not change. A change in the mailbox provisioning code causes the system to process the mailbox again. Such a change also causes the custom protocol settings on the mailbox to be restored to standard protocol entitlements.
For more information about how to manage mailbox quotas and types, see the following Microsoft Knowledge Base article:
Article ID: 2978520 - Last Review: 11 Dec 2015 - Revision: 1