Office 365 Advanced Archiving capablities hosts archive mailboxes for your on-premises or cloud users in Exchange Online. You can manage the advanced archiving capablities using the Office 365 portal (https://portal.microsoftonline.com). This document shows how to perform some of the common tasks in Office 365.

Create a cloud-based archive for a user

Perform the following steps to create an archive for a new user:

  1. Use the Office 365 portal to create a user account. We must have an Office 365 license available. During user account creation, we will be asked to assign one Office 365 license to each new user. For details, see Create or Edit Users.
  2. Enable an archive. For details, see Enable an Archive Mailbox.

Remove a user’s cloud-based archive

When we remove a user’s archive, it is disconnected from the user. Disconnected archives are retained in Exchange Online for a period of 30 days. During this period, we can reconnect the archive to the user. After 30 days, the archive is permanently deleted from Exchange Online. For details, see Disable the archive mailbox.

Note: If we remove the user’s Office 365 account, we can’t connect another user to the archive or perform a discovery search on the user’s archive. We can keep the account active but configure it to block user access. This preserves the ability to include the user’s archive in a discovery search.

 

Get archive size

Depending on the Office 365 subscription, each user’s archive is configured with a fixed amount of storage space, known as an archive quota. When a user’s archive reaches the archive quota, new messages can’t be added to it.

For Exchange Online Plan 1 customers, the quota is 25 Gb. Plan 2 customers receive unlimited storage for their archive, but the default quota is set to 100 Gb. In the unlikely event that a user reaches this quota, contact Office 365 support to request more storage space for the archive mailbox.

 

To check the size of a user’s archive, first connect PowerShell to Exchange Online and then run this command:

Get-MailboxStatistics <user name> -Archive

 

To retrieve archive size and related details for multiple users and have the results formatted as a table, use this command:

Get-Mailbox -Filter {ArchiveStatus -eq "active"} | Get-MailboxStatistics -archive | ft DisplayName,ItemCount,TotalItemSize,StorageLimitStatus -auto

 

Place an archive on litigation hold

To meet various regulatory, legal or business requirements, we may need to preserve messages in an archive. Exchange Online allows us to place a user on litigation hold. This protects messages in an archive from being permanently deleted. Additionally, if a user or a process makes any changes to certain message properties, a copy of the original item is created before saving the change. When a discovery search is performed, any deleted messages or versions of changed messages are also returned in search results if they match the search criteria. For details, see Put a mailbox on litigation hold.

 

Perform a discovery search

Authorized users who are members of the Discovery Manager RBAC role group can use Multi-Mailbox Search to perform a discovery search on your users’ archives. Based on the search options selected, you can either view an estimate of number of messages the search will return or have messages returned in search results copied to a discovery mailbox for further review. We can also export messages from the discovery mailbox to a PST file. For more details, see Multi-Mailbox Searches.

 

Export archive or discovery results to a PST file.

We can export a user’s archive to a PST file by using Microsoft Outlook. This allows your organization to keep an offline copy of the archive to meet various business requirements, including providing a copy a user’s archive or discovery search results to internal or external counsel. For more details, see Export Multi-Mailbox Search Results to an Outlook Data File (.pst).