On Oct 31, 2017, RPC over HTTP will be deprecated in Exchange Online in favor of MAPI over HTTP, a modern protocol that was launched in May 2014. This change affects you if you're running Outlook 2007 because it won't work with MAPI over HTTP. To continue email connectivity, Outlook 2007 customers will have to update to a newer version of Outlook or use Outlook on the web. This change may also affect you if you're running Outlook 2016, Outlook 2013, and Outlook 2010 as you must make sure that the latest cumulative update for the version of Office that you have is installed.
What is RPC over HTTP? What happens on October 31, 2017?
RPC over HTTP, also known as Outlook Anywhere, is a legacy method of connectivity and transport between Outlook for Windows and Exchange. In May 2014, Microsoft introduced MAPI over HTTP as a replacement for RPC over HTTP.
On October 31, 2017, Exchange Online mailboxes in Office 365 will require connections from Outlook for Windows to use MAPI over HTTP. Outlook for Windows clients that use RPC over HTTP (for example, Outlook 2007) will be unable to access Exchange Online mailboxes.
Why is RPC over HTTP being replaced by MAPI over HTTP?
MAPI over HTTP offers the following benefits:
- Provides faster connection times to Exchange.
- Improves the connection resiliency when the network drops packets in transit.
- Enables more secure sign-in scenarios such as multi-factor authentication for Office 365.
- Provides the extensibility foundation for third-party identity providers.
- Removes the complexity of RPC over HTTP dependency on legacy RPC technology.
I'm using Office 365 with Outlook 2016, Outlook 2013, or Outlook 2010. What actions do I have to take?
Make sure that you use Outlook for Windows clients that are updated to work with MAPI over HTTP.
The best and recommended option is to move to the latest version of Office 2016 as part of Office 365 ProPlus. If you're unable to move to Office 365 ProPlus by October 31, 2017, make sure that Office applications in your organization are updated with the most recent cumulative update.
The following are the minimum required Office updates to install to avoid connectivity disruption on October 31, 2017.
- Office 2016: The December 8, 2015 update
- Office 2013: Office 2013 Service Pack 1 and the December 8, 2015 update
- Office 2010: Office 2010 Service Pack 2 and the December 8, 2015 update
The December 8, 2015 updates for Office are listed in the following Microsoft Knowledge Base article:
December 8, 2015, update for Office
We recommend that you keep applications updated with the most recent product updates as several MAPI over HTTP issues have been fixed since December 2015.
Additionally, you may have to make sure that Outlook clients aren't using a registry key to disable MAPI over HTTP. For more information, see in the following Microsoft Knowledge Base article:
Outlook 2013 or 2016 may not connect using MAPI over HTTPs as expected
I'm using Office 365 with using Outlook 2007 or earlier. What actions do I have to take?
MAPI over HTTP was not backported to Outlook 2007 or earlier versions. Therefore, Outlook 2007 and earlier versions will be unable to connect to Office 365 mailboxes on October 31, 2017. If you're using Outlook 2007, you must update your version of Outlook for Windows before October 31, 2017. Or, use Outlook on the web to access Exchange Online mailboxes through the Office 365 portal (portal.office.com
Additionally, make sure that you don't have any Outlook add-ins or third-party apps that rely on the RPC over HTTP protocol to connect to Office 365 data.
Why is MAPI over HTTP not backported to Outlook 2007?
MAPI over HTTP was released after the end of Mainstream Support for Office 2007
. By October 31, 2017 when RPC over HTTP is deprecated, Office 2007 will be out of Extended Support.
Does this deprecation affect Outlook for Mac, Outlook for iOS and Android, Outlook for Windows 10 Mobile or Outlook on the web?
No. This only applies to Outlook for Windows.
Where can I find more information about MAPI over HTTP?
For more information about MAPI over HTTP, see the following resources:
Does this deprecation in Office 365 affect customers using Exchange Server 2007, Exchange Server 2010, Exchange Server 2013, and Exchange Server 2016?
No. Customers using RPC over HTTP to connect Outlook for Windows and on-premises Exchange Server continue to do so. This change only affects customers using Outlook for Windows to connect to Exchange Online mailboxes in Office 365. .
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