- Encryption between Outlook and Exchange Server is disabled.
- You are not using Outlook Anywhere to connect to Microsoft Exchange.
If you are using Outlook AnywhereIf you are using Outlook Anywhere, install the appropriate Microsoft Outlook hotfix.
Outlook 2010This issue is fixed in the Outlook 2010 hotfix package that is dated February 11, 2014. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
Outlook 2013This issue is fixed in the Outlook 2013 hotfix package that is dated April 8, 2014. For more information, click the following article number to view the article in the Microsoft Knowledge Base:
Note Outlook Anywhere is also known as RPC over HTTPS (Secure HTTP). As indicated by the term HTTPS, Outlook Anywhere connects to Exchange by using a Secure Sockets Layer (SSL) connection.
If you are not using Outlook AnywhereIf you cannot install the latest version of Outlook 2010 or Outlook 2013 and you are not using Outlook Anywhere, you can work around this problem if your mailbox is located on Microsoft Exchange Server 2010, or an earlier version.
To work around this problem, try to enable RPC encryption between Outlook and Exchange. To do this, follow these steps:
- In Control Panel, open the Mail item.
- Click Show Profiles.
- Select your profile, and then click Properties.
- Click E-mail Accounts.
- Select the Microsoft Exchange Server account, and then click Change.
- In the dialog box that contains your mailbox server and user name, click More Settings.
- In the Microsoft Exchange Server dialog box, click the Security tab.
- Click to select the Encrypt data between Microsoft Outlook and Microsoft Exchange check box, and then click OK.
Important If the check box is unavailable (dimmed), you are most likely connected to Microsoft Exchange Server 2013, or you are using a mailbox in Office 365. In this case, RPC encryption cannot be enabled. Be aware that Outlook Anywhere (RPC over HTTPS) connections are secure as they are encrypted by using Secure HTTP (HTTPS).
- Click Next,and then click Finish.
- Click Close, and then click OK.
For more information about how to configure junk email settings in Outlook, see the following Microsoft website, depending on the version of Outlook that you are using: