Article ID: 2029293 - View products that this article applies to.
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Am I using Office 365 after the service upgrade?
When a Microsoft Office 365 pre-upgrade user tries to open Microsoft Outlook, the user receives the following error message:
Unable to open your default e-mail folders. The Microsoft Exchange Server computer is not available. Either there are network problems or the Microsoft Exchange Server computer is down for maintenance.
To fix this issue, make sure that the Encrypt data between Microsoft Office Outlook and Microsoft Exchange option is selected in Outlook. To do this, follow these steps.
Outlook 2013 and Outlook 2010
This issue may occur because Exchange Online forces an encrypted connection between the client (Outlook) and the server.
By default, Outlook 2013, Outlook 2010, and Office Outlook 2007 "encrypts" data between client and server. Therefore, this scenario occurs only in environments in which this setting is manually overwritten.
Still need help? Go to the Office 365 Community
Article ID: 2029293 - Last Review: November 21, 2013 - Revision: 25.0