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Summary: Exchange Online Administrators play a vital role in safeguarding an organization’s data. While emails and contacts often take precedence, protecting additional data like calendars, tasks, and notes is crucial. This is achieved through retention policies and tags, ensuring data integrity and management.

All data generated by an organization and its staff holds significance, even though its relevance may vary. Exchange Online Administrators bear the responsibility of overseeing and safeguarding all data, necessitating proactive measures to protect every user’s information. While the main emphasis is typically on safeguarding emails and contacts due to their critical role in business operations, it’s equally vital to protect other data components such as calendars, notes, archives, and tasks.

Administrators safeguard data through the implementation of retention policies, a strategy that preserves content rather than immediately deleting it. These policies incorporate a ‘retention tag,’ outlining whether the content should be archived and the specific timeframe for deletion. Retention policies play a crucial role in managing the lifecycle of all mailbox items.

In addition to mailbox items, retention tags can be applied to various default folders. This includes key folders like Calendar and Tasks, which can benefit from retention policies.

Default Folders Usage
Calendar A calendar folder can save important dates, events, meetings, and appointments.
Tasks When a user creates a task to complete in the future, its description is saved in the Task folder. It is also savable using retention tags.
Clutter A clutter folder can save the lesser essential emails and declutter the Inbox.
Deleted Items When emails are deleted from the Inbox, they reach the Deleted Items default folder. It will support retention tags also.
Drafts The drafts folder saves the messages the user does not send to other accounts.
Journal This folder saves the user’s actions and is placed in the timeline view in Outlook.
Notes Notes created in Outlook are saved in this folder. They can be protected using retention tags.
Outbox Outbox temporarily contains outgoing messages until they are entirely processed in the Hub Transport Server.
Sync Issues Synchronization logs are present in the Sync Issues folder.
Archive The archive folder is the destination for saving older messages present in Outlook. The retention policies can keep archive mailbox messages. But it will work only in Exchange Online.

How to Create a Retention Tag?

Follow these steps to create a Retention tag for the Calendar folder-

  1. Open the Microsoft 365 Admin Center. Click on Show all and select Compliance.Open the Microsoft 365 Admin Center
  2. Microsoft Purview compliance portal will open. Expand the Data lifecycle management under Solutions and select Exchange (Legacy).Expand the Data lifecycle management
  3. Move to the MRM Retention tag and click on the +New on the plus New tag
  4. Type the appropriate Name and Description and move on to Next.Type the appropriate Name and Description
  5. Check the Automatically to default folder option. Expand the Apply tag to this folder option and select Calendar. Click on Next.Apply tag to this folder option
  6. Define the retention settings, which include the specific Retention Period and the Retention Action to be taken after the period.Define the retention settings
  7. Review all the entries and click on Finish.
How to apply the Retention Tag to the Calendar?
  1. Go to the Outlook application where you have connected the same office 365 account.
  2. Choose Calendar and right-click on it. Choose to apply the retention tags.
    Choose Calendar
Things to keep in mind

TThe retention policy safeguards the chosen folder from deletion. However, there are some crucial considerations to keep in mind before creating retention tags:

  1. In Exchange Online, you can also create retention tags on Calendar and Tasks.
  2. You can apply retention tags only on default folders. But, you can use only limited actions on them like –
    • Delete and Allow Recovery
    • Permanently Delete
  3. You cannot create a tag to move messages to an archive folder. It would help if you created Default Policy Tag or personal tags to move the messages to the archive mailbox.
  4. Retention policy tags will not work on Contacts folders.
  5. You can apply only a single tag to the default folder. For example, no other tag will be applicable if you have added a retention tag on Inbox.
Retention Policies are not Backups

Microsoft 365 operates on a shared tenancy model, wherein both users and the platform share responsibility for data security. It adopts a Software as a Service (SaaS) model, with Microsoft and others managing certain components. While Office 365 oversees the physical infrastructure and ensures mailbox availability, data security largely relies on users. It’s essential to recognize that retention policies are not equivalent to backups. Backups create offline copies, whereas retention protects data from deletion. Failure to enable retention policies can leave your data vulnerable to abrupt deletions.


Creating a Retention tag for Calendar and other folders is a straightforward process. However, it’s essential to understand that retention is not synonymous with backup. While retention helps manage data deletion, taking a backup of your Office 365 mailbox is crucial to minimize the risk of data loss. You can achieve this through either manual methods or by using professional Export Office 365 to PST software. While the manual process only saves emails in PST format, professional software can efficiently export entire Office 365 mailboxes to PST, including emails, Contacts, Calendars, notes, and other essential items.

Kernel Office 365 Backup and Restore software are specifically designed to efficiently back up an unlimited number of mailboxes in the PST file format. This powerful tool empowers Exchange Administrators to safeguard entire accounts, effectively protecting them from various threats and ensuring data security.