What is Email archiving in Office 365 ?
Email archiving is a concept stuck between generations of technology. After years of backing up archives in PST files, there is a question of how does this work with the cloud and Exchange Online?
Archiving is an often overlooked feature of email services but there are many scenarios where it is useful. Users can better organize mailboxes and free up much needed storage space; businesses are able to preserve records of email communications, and ensure data security and compliance needs.
Microsoft offer their own archiving service for Exchange Online and there are endless third party add-ins. While the Microsoft solution is very simple and easy to use, its simplicity comes at a cost. The archiving features do not offer much flexibility in implementation and some features are restricted to upper-level subscriptions with the latest release edition of Outlook.
Email archiving within Microsoft Office 365 is established by an In-Place Archive. The archive appears similar to a normal mailbox, which includes the inbox, outbox, drafts, etc. It essentially displays like another set of folders in Outlook. From a user and administrator perspective, this is the preferred archiving method. It removes the legacy PST format, which involved storing email data on a user's PC or on a server, that lacked flexibility compared to an In-Place Archive.
While the In-Place Archive appears similar to adding on a second mailbox, its features are significantly limited. Particularly, the archive mailbox cannot be accessed from mobile devices (Exchange ActiveSync does not support archive mailboxes). Additionally, email in the In-Place Archive can still be interacted with (e.g. replies & forwarding), however difficulties can arise if attempting to move emails back into the main mailbox. For this reason, once emails are in the In-Place Archive, they should be treated as if they cannot be removed.
Users can archive emails via two primary methods with the In-Place Archive:
- Manually adding emails to the archive (dragging and dropping, or right-click and moving).
- Retention policy that automatically archives emails after a period of time (default is two years; set by administrator).
Unfortunately users cannot set inbox rules of their own to automatically archive email. They must manually add emails to the archive. A sort-of workaround, is to create a 'dummy' archive folder in their main mailbox. Emails can stay in that folder until they are archived using the two year retention policy.
Finally, the In-Place Archive is switched off by default, even for accounts entitled to the feature. Administrators must manually enable the archive for every mailbox that will be using it.
In-Place Hold & Litigation Hold
Microsoft have two other methods of retaining email, In-Place Hold and Litigation Hold. Strictly speaking, these holds are not archives. But from a business perspective, they are effective methods of preserving email. The two holds are managed by administrators to ensure mailboxes are accurately stored when necessary. They are not user-controlled archives.
The In-Place Hold is a rules based hold that targets certain types of email using retention policies. A Litigation Hold archives all emails. Both holds will prevent emails from being deleted from a user's main mailbox and archive mailbox. The emails will also be preserved as they were received, preventing a user from altering them. These holds are obviously useful for compliance purposes.
Availability of these type of holds depends on the Office or Exchange subscription and/or product purchased.
Archive storage capacity
A common question about Microsoft's archiving feature is: how large is the storage capacity?
Earlier this year Microsoft boosted the capacity for some Office 365 plans to unlimited. It works by first allocating the archive mailbox 100 GB of storage. Once it is filled, more capacity is added in blocks or allocations. Microsoft have not stated how large these further allocations are or if there is a eventual storage limit to them.
A key point to note however is that Office 365 Business plans (not Enterprise) do not have an unlimited archive. They currently have an archive storage limit of 50GB (on top of the 50GB for their inbox mailbox).
Unlimited archiving in Office 365
In Office 365, archive mailboxes provide users with additional mailbox storage space. After a user's archive mailbox is enabled, up to 100 GB of additional storage is available. When the 100 GB storage quota is reached, organizations had to contact Microsoft to request additional storage space for an archive mailbox. That's no longer the case. The new unlimited archiving feature in Office 365 (called auto-expanding archiving) provides an unlimited amount of storage in archive mailboxes. Now, when the storage quota in the archive mailbox is reached, Office 365 automatically increases the size of the archive, which means that users won't run out of mailbox storage space and administrators won't have to request additional storage for archive mailboxes.
Before you begin
You have to be a global administrator in your Office 365 organization or a member of the Organization Management role group in your Exchange Online organization to enable auto-expanding archiving for your entire organization or for specific users. Alternately, you have to be a member of a role group that's assigned the Mail Recipients role to enable auto-expanding archiving for specific users.
A user's archive mailbox has to be enabled before you can enable auto-expanding archiving. A user must be assigned an Exchange Online Plan 2 license to enable the archive mailbox. If a user is assigned an Exchange Online Plan 1 license, you would have to assign them a separate Exchange Online Archiving license to enable their archive mailbox
You can't use the Exchange admin center or the Security & Compliance Center to enable auto-expanding archiving. You have to use Exchange Online PowerShell. To connect to your Exchange Online organization using remote PowerShell.
Enable auto-expanding archiving for your entire organization
You can enable auto-expanding archiving for your entire organization. After you turn it on, auto-expanding archiving will be enabled for existing user mailboxes and for new user mailboxes that are created. When you create new user mailboxes, be sure to enable the user's main archive mailbox so the auto-expanding archiving feature will work for the new user mailbox.
- Connect to Exchange Online PowerShell
- Run the following command in Exchange Online PowerShell to enable auto-expanding archiving for your entire organization.
Enable auto-expanding archiving for specific users
Instead of enabling auto-expanding archiving for every user in your organization, you can just enable it for specific users. You might do this because only some users might have a need for a very large archive storage.
When you enable auto-expanding archiving for a specific user, the following two configurations changes are also made:
- The storage quota for the user's primary archive mailbox is increased by 10 GB (from 100 GB to 110 GB).
- The storage quota for the Recoverable Items folder in the user's primary mailbox is increased by 10 GB (also from 100 GB to 110 GB). This change is applicable only if the mailbox in on hold.
- Connect to Exchange Online PowerShell
- Run the following command in Exchange Online PowerShell to enable auto-expanding archiving for a specific user. As previously explained, the user's archive mailbox (main archive) must be enabled before you can turn on auto-expanding archiving for that user.
Enable-Mailbox <user mailbox> -AutoExpandingArchive
Verify that auto-expanding archiving is enabled
To verify that auto-expanding archiving is enabled for your organization, run the following command in Exchange Online PowerShell.
A value of True indicates that auto-expanding archiving is enabled for the organization.
To verify that auto-expanding archiving is enable for a specific user, run the following command in Exchange Online PowerShell.
A value of True indicates that auto-expanding archiving is enabled for the user.
As previously explained, 10 GB is added to the storage quota of the user's primary archive mailbox when you run the Enable-Mailbox -AutoExpandingArchive command.
Keep the following things in mind after you enable auto-expanding archiving:
If you run the Set-OrganizationConfig -AutoExpandingArchive command to enable auto-expanding archiving for your organization, you don't have to run the Enable-Mailbox -AutoExpandingArchive on individual mailboxes. Note that running the Set-OrganizationConfig cmdlet to enable auto-expanding archiving for your organization doesn't change the AutoExpandingArchiveEnabled property on user mailboxes to True.
Similarly, the values for the ArchiveQuota and ArchiveWarningQuota mailbox properties aren't changed when you enable auto-expanding archiving. In fact, when you enable auto-expanding archiving for a user mailbox and the AutoExpandingArchiveEnabled property is set to True, the ArchiveQuota and ArchiveWarningQuota properties are just ignored. Here's an example of these mailbox properties after auto-expanding archiving is enabled for a user's mailbox.
ArchiveQuota and ArchiveWarningQuota properties are ignored after you enable auto-expanding archiving: