Office 365: Set up Online Archives

Pre-requisites (Power Shell):

- Run PowerShell as Admin - Credentials for Global Admin account  - Disconnect from PowerShell session when done (article 1)

Step #1: Assign appropriate licenses

Exchange Online Plan 1/2 - Email only (no software)Business Premium - 50 GB mailbox; 50 GB Archive ($12.50/month)Office 365 E3 - 100 GB mailbox; Unlimited archive($20/month)Office 365 E5 - Adds compliance (DLP, threat intelligence, lockbox, MDM) + phone system ($35/month)

https://portal.office.com > Admin section > Billing > Purchase ServicesLog in as Global Admin

Step #2: Set up an archive and deletion policy for mailboxes

Example: Archive after 1 or 2 years; Fully delete after 5 or 7 years

https://outlook.office365.com/ecp/

Compliance Management > Retention TagsCreate '1 or 2 Year Move to Archive' (Type: Default - Retention 365 or 730 days - Retention Action: ArchiveCreate '5 or 7 Year Permanently Delete' (Type:Default - Retention: 1825 or 2555 Days - Retention Action: Delete)Create 'Deleted Items 5 Years Delete and Allow Recovery' (Type: Deleted Items - Retention: 1825 Days - Retention Action: Delete)

Compliance Management Retention PoliciesNew policy (i.e. CPL Archive and Deletion Policy)Add three policies created above

Reference:

https://docs.microsoft.com/en-us/office365/securitycompliance/set-up-an-archive-and-deletion-policy-for-mailboxes#create-a-custom-archive-default-policy-tag

Step #3: Enable archive mailboxes in Compliance Center

https://compliance.microsoft.com/informationgovernance - Archive- or - 

https://outlook.office365.com/ecp/ - Recipients - MailboxesSelect and enable 'in-place archiving' (or Select all - More Options - Archive - Enable and bulk edit)Assign 'Retention Policy' created in Step #2

Reference:

https://docs.microsoft.com/en-us/microsoft-365/compliance/enable-archive-mailboxes?view=o365-worldwide

Step #4: Enable Unlimited Archiving

Reference:

https://docs.microsoft.com/en-us/microsoft-365/compliance/enable-unlimited-archiving?view=o365-worldwide


2023-11—06:

We have to use PowerShell to enable Auto expanding archiving, unfortunately we don't have option to enable through GUI.

 
Please follow below steps to enable Auto expanding  archiving.
  • Install-Module ExchangeOnlineManagement
  • Import-Module ExchangeOnlineManagement
  • Connect-Exchange
  • Set-OrganizationConfig -AutoExpandingArchive   
(Note: If we run this command auto expanding will enable to every user in organization) 
  • Enable-Mailbox <user mailbox> -AutoExpandingArchive 
(Note: If we run this command, it's only applying to specific mailbox, please make sure to change the <user mailbox> to User mail ID)

ARCHIVE


1. Open Windows PowerShell as an admin, then copy and paste the following PowerShell commands, while pressing enter and following the steps on the screen.


> Set-ExecutionPolicy Remotesigned

> Install-module -name Exchangeonlinemanagement

> Connect-Exchangeonline

> Enable-Mailbox "user mailbox" -AutoExpandingArchive


Now, the mailbox will keep expanding when need arises and will always provide additional space to archive, until it reaches 1.5TB.


Adjusting the warning quota


Connect to exchange online powershell module.


1. Open PS as and administrator

2. Connect-exchangeonline

3. Get-mailbox -identity user@domain.com -archive | fl name


You will get the archive name in the output. then run the command below.


4. set-mailbox "archive name from above" -IssueWarningQuata 95GB -ArchiveWarningQuota 95GB


5. Get-mailbox "Archive name from above" | select *quota*


You can then confirm that the above mentioned two quotas  have been set to 95 respectively.