In order to keep your Outlook running as efficiently as possible, we are recommending to keep your mailbox size as small as possible. Large mailboxes make browsing and searching messages slower, can cause performance degradation, crashes, and are more prone to corruption. The maximum allowed user mailbox size is 100 GB. This limit, known as mailbox quota, is mandated by Microsoft and cannot be increased (see Exchange Online Limits for more info).
Microsoft Exchange Online & Outlook offers a feature called archiving that, once enabled for your mailbox, will reduce its size by automatically moving older messages from the main mailbox to the separate archive mailbox called Online Archive in Outlook desktop app and InPlace Archive in Outlook web app. You may request automated archiving to be enabled for your main mailbox or a shared mailbox by opening a ticket. How old a message has to be before it gets archived is determined by which retention policy was assigned to your mailbox when automated archiving was enabled. By default, the 365 days (1 year) policy gets assigned but if this is not sufficient to reduce the mailbox size below 90 GB, then 180 days (6 months) or 90 days policy can be assigned.
If you had automated archiving enabled in Lotus Notes prior to migrating to Outlook, your Lotus Notes archive mailbox was migrated to Outlook's archive mailbox and any messages that are older than two years will continue to be archived automatically. The automated archiving, however, is not enabled for any mailboxes created after 2016.
Accessing Online Archive / InPlace Archive
Your archive mailbox is called Online Archive in Outlook desktop app and InPlace Archive in Outlook web app.
Outlook web app
You can find the archive under your folder list on the left. In Outlook web app it is called In-Place Archive - Your Name but you must click on it expand and see its list of folders.
Outlook desktop app
You can find the archive on your folder list on the left side. It will appear below the list of folders belonging to your main mailbox, and you may need to scroll down to see it if your mailbox has lots of folders. In Outlook it is called Online Archive followed by the e-mail address of the main mailbox. You must expand this header by clicking on the little triangle icon that appears on the front of Online Archive - UWinID@uwindsor.ca to view the list of your archive folders:
NOTE: If you click on the header itself, no messages will be displayed. This is working as designed. You must click on one of the folders listed under the header to display its contents.
Archiving Settings
Once automated archiving was enabled, you can modify the archiving settings on individual folders or on on the entire mailbox, by assigning a different archiving policy to the folder or the mailbox. To enable archiving for the entire mailbox, follow these steps:
- Launch Outlook desktop app for Windows and go to mail.
- Select the account/mailbox that you want to enable archiving for by clicking on the e-mail address.
- On the menu ribbon, click on Folder tab then on the Policy button.
- In the dialogue box go to Online Archive section on the Policy tab and select the duration of your choice:
- 90 days
- 180 days (6 months)
- 1 year
- 5 years
- Never.
Note that the "parent folder policy" (default setting) is 2 years.
Archive Folder
The Archive folder is one of the default folders in Outlook, like Inbox, Sent Items, and the Deleted Items folder. You can move messages to the Archive folder without deleting them by clicking the Archive button. however, "archiving" messages this way doesn’t reduce mailbox size since the messages are still stored in the user’s primary mailbox but a different folder.
