How to ensure all M365 emails are protected by Clumio


Clumio's M365 backup solution allows customers to configure backups as frequently as every hour. However, within that hour it is possible for an end user to create or receive a message, and forcibly delete the message from the Mailbox, Deleted Items, and Recoverable Items folders before Clumio has an opportunity to protect it. For customers requiring all messages to be protected, Clumio cannot guarantee that behavior without administrative changes to M365.

Recommended solution

Microsoft offers a number of solutions to protect against forced message deletion, but the method Clumio recommends is by using Retention Labels. Retention Labels allow Global Administrators to specify how long to retain messages with daily granularity, and can be applied as broadly as all mailboxes or as granular as by message content. As soon as the item is created, the Retention Label timer starts and protection works as follows:

If the item is modified or deleted during the retention period: A copy of the original item is created in the Recoverable Items folder and retained until the end of the retention period, when the copy in the Recoverable Items folder is permanently deleted within 14 days after the item expires.

Clumio protects all items in the Mailbox, Deleted Items and Recoverable Items folders, so in order to ensure a message is backed up regardless of user behavior, the Retention Label should be configured to retain data longer than Clumio backup frequency.


  • Backup frequency = 0-23 hours; Configure Retention Label for at least 1 day
  • Backup frequency = Daily; Configure Retention Label for at least 2 days
  • Backup frequency = Weekly; Configure Retention Label for at least 8 days

Microsoft provides the following article explaining How to create and apply Retention Labels.


Contact [email protected] in case of any clarifications or questions.