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PennO365 Email Quotas



Quotas for Mailboxes

Mailbox Size Limits

The maximum size for mailboxes in PennO365 is 100GB for user accounts and 50GB for shared accounts. Microsoft has its own Exchange Online Limits that set the cap of what can be made available in the PennO365 tenant.


Mailbox Size Increases - Online Archive with Auto-Expanding Archive

The PennO365 mailbox size limits are the largest allowed by Microsoft so they cannot be expanded outright; However, turning on the auto-expanding archive allows the account to be larger than 100GB. Online archiving expands the account to 110GB and then auto-expands by increments of 10GB until the archive reaches 1.5TB.

After online archiving is turned on, retention policies must be applied to the mailbox folders.

Online Archiving can be requested by IT Support via the O365 tile in Support Center.


Managing Mailbox Size

When possible, we suggest that users manage the size of their mailboxes. Some options for mailbox management include:

  • Deleting unneeded emails
  • Emptying the Deleted Items folder on a regular basis
  • Setting Outlook to empty the Deleted Items folder upon exit
  • Using online file-sharing tools to share large files/attachments



Quotas for Mailbox Folders

Restrictions on Numbers of Items in Mailbox Folder

Once a folder in the mailbox gets to 100,000 items, performance may be degraded. It is the best practice to check the item count when inconsistent or unusual problems are reported with the PennO365 mailbox.


Viewing Number of Items in Folder

There are several ways to view the number of items in a folder.

  • Click the gear in the top right
  • Scroll to the bottom of the menu and click View all Outlook settings
  • Go to General, then Storage

This view will show the number of messages in each folder.

An item count may naturally show up on the Status Bar at the bottom of the Outlook window. If it does not:

  • Right-click the Status Bar and check Items in View
  • Right-click the folder and click Properties
  • On the General tab, select Show total number of items