'%3e%3cpath%20d='M8%200C12.4183%200%2016%203.58172%2016%208C16%2012.4183%2012.4183%2016%208%2016C3.58172%2016%200%2012.4183%200%208C0%203.58172%203.58172%200%208%200ZM11.6162%204.38379C11.2257%203.99337%2010.5927%203.99338%2010.2021%204.38379L8%206.58594L5.79785%204.38379C5.40732%203.99334%204.77429%203.99329%204.38379%204.38379C3.99331%204.77429%203.99335%205.40733%204.38379%205.79785L6.58594%208L4.38379%2010.2021C3.99348%2010.5927%203.99341%2011.2257%204.38379%2011.6162C4.77426%2012.0066%205.40734%2012.0065%205.79785%2011.6162L8%209.41406L10.2021%2011.6162C10.5927%2012.0066%2011.2257%2012.0067%2011.6162%2011.6162C12.0067%2011.2257%2012.0066%2010.5927%2011.6162%2010.2021L9.41406%208L11.6162%205.79785C12.0066%205.40735%2012.0066%204.77429%2011.6162%204.38379Z'%20fill='%23080E17'%20fill-opacity='0.46'/%3e%3c/g%3e%3cdefs%3e%3cclipPath%20id='clip0_3761_713'%3e%3crect%20width='16'%20height='16'%20fill='white'/%3e%3c/clipPath%3e%3c/defs%3e%3c/svg%3e)
How to Increase a Nearly Full Exchange Online Room Mailbox
Question details
The administrator needs to know how to increase the capacity of an Exchange Online room mailbox that is approaching its storage limit without necessarily assigning a new license.
- Product
- Microsoft Exchange Online
- Device & OS
- not provided
- Scenario
- Managing resource mailboxes and resolving storage quota warnings for a room mailbox.
- Observed behavior
- The room mailbox is nearing its maximum storage capacity, preventing future calendar invites if the limit is reached.
Ensure you have Exchange Administrator or Global Administrator privileges in your Microsoft 365 tenant to view mailbox properties and manage licenses.
Clean Up Data and Apply Retention Policies
Free up space in the room mailbox by removing old meeting requests and implementing retention policies before considering paid licenses.
Unlicensed room mailboxes in Exchange Online are typically limited to 50 GB. Before purchasing a license, administrators can safely remove historical data to reclaim space.
Log into the Exchange Admin Center (EAC), navigate to Recipients > Resources, and select the room mailbox to view its current storage usage.
Go to the Microsoft Purview compliance portal and set up a retention policy targeting the room mailbox to automatically delete meeting items older than a specified duration (e.g., 365 days).
Use Exchange Online PowerShell to connect to your tenant and run the 'Search-Mailbox' or 'New-ComplianceSearchAction' cmdlets to purge the Deleted Items and Recoverable Items folders for that specific resource mailbox.
Assign an Exchange Online Plan 2 License
If cleanup is insufficient, assign a qualifying license to automatically increase the room mailbox limit to 100 GB.
Enhance Your Team's Productivity with WPS Office
While you manage your Exchange infrastructure, empower your team with WPS Office. It's a lightweight, free, and highly compatible Office alternative that reduces overhead while providing a familiar environment for all document creation needs.
- 1. Download the software: Visit the official WPS Office website and click on the free download button.
- 2. Install the suite: Run the installer package and follow the quick setup wizard to install WPS Office on your device.
- 3. Open existing files: Launch WPS Office and directly open your existing Word, Excel, or PowerPoint files without worrying about formatting issues.
Frequently Asked Questions
Can I increase a room mailbox beyond 50 GB for free?
No. The maximum storage limit for an unlicensed room mailbox in Exchange Online is 50 GB. To increase this capacity, you must clean up existing data or purchase and assign a qualifying license.
Will an Exchange Online Plan 1 license increase the room mailbox size?
No. Exchange Online Plan 1 also provides a maximum mailbox size of 50 GB. To increase the limit to 100 GB, you must assign an Exchange Online Plan 2 license.
How do I check the storage size of an Exchange Online room mailbox?
You can view the storage usage in the Exchange Admin Center under Recipients > Resources, or by using the Get-MailboxStatistics PowerShell cmdlet targeting the room mailbox identity.
Can I enable an In-Place Archive for a room mailbox?
Yes, but doing so requires the room mailbox to be properly licensed. You cannot enable archiving on an unlicensed resource mailbox to circumvent the 50 GB storage limit.
