Some folders are not visible in Outlook on the web

When you view a mailbox in Outlook on the web (formerly known as Outlook Web App [OWA]), some of your folders are not visible. When this issue occurs, it's typically the Sent Items folder that's not visible.
This issue occurs when the mailbox contains too many folders. The maximum number of folders in a single mailbox that Outlook on the web can display at one time is 10,000. 

To confirm that this is the issue that you're experiencing, determine the number of folders in the mailbox. To do this, follow these steps:
  1. Do one of the following, as appropriate for your situation:
  2. Run one of the following commands:
    • To display the results on the screen, run the following command:
      (Get-MailboxFolderStatistics <>).count
    • To send the results to a .txt file, run the following command:
      (Get-MailboxFolderStatistics <>).count > c:\output.txt
To resolve this issue, reduce the total number of folders in the mailbox to fewer than 10,000.
Still need help? Go to the Office 365 Community website or the Exchange TechNet Forums.

Article ID: 2849181 - Last Review: 10/01/2015 06:19:00 - Revision: 7.0

Exchange Server 2016 Enterprise Edition, Exchange Server 2016 Standard Edition, Microsoft Exchange Server 2013 Enterprise, Microsoft Exchange Server 2013 Standard, Microsoft Exchange Server 2010 Enterprise, Microsoft Exchange Server 2010 Standard, Microsoft Exchange Online

  • kbsurveynew kbtshoot kbexpertiseinter o365 o365a o365e o365p o365m o365022013 KB2849181