Outlook 2016If you have Outlook 2016 and you're connected to an Exchange Server 2016 or Exchange Online mailbox by using Cached Exchange Mode, Outlook is likely using Exchange FAST search to query the mailbox. To optimize performance, Exchange FAST search shows the same behavior that's described in the Cause section.
To work around this behavior, force Outlook 2016 to use the locally cached Windows Desktop Search (WDS) index. To force Outlook to fall back to WDS search, change the search scope to Subfolders, All Mailboxes, or All Outlook Items as shown in the following screen shot:
Outlook 2013 and earlier versionsIf you have Outlook 2013 or an earlier version, you might have Outlook configured to connect to the Exchange email account by using online mode. To work around this behavior, you can use Outlook in Cached Exchange Mode. For more information, see Turn on or off Cached Exchange Mode.
Article ID: 3166063 - Last Review: Jun 1, 2016 - Revision: 1