NOTE: This article provide information to Local Administrator of organisations with identified users using managed desktops with Office 2010 or later clients and connecting to Exchange Online using basic authentication with the below protocol:
- Remote Procedure Call (RPC)
Microsoft has replaced basic authentication protocols for Exchange Online with modern connectivity that enables additional layers of security. The NHSmail team has put in place a strategy to separate out the retirement of these protocols into a new schedule before June 2023 to reduce any potential impact or disruption to organisations and their users.
The below table provides an overview of this schedule:
| Protocol | Retirement date |
| RPC | 27th April 2023 (evening) |
This means that some users using managed desktops with Microsoft Office 2010, 2013, 2016 for Windows and using Remote Procedure Call (RPC) over HTTP will stop sending and receiving emails. RPC over HTTP has been replaced by MAPI over HTTP, a modern protocol that was launched in May 2014.
A communication will be sent out to organisations appearing in our reporting to raise awareness and guide them through the process.
IMPORTANT NOTE: Please note that the below Office clients do not support modern authentication and it is recommended to upgrade to the most recent Office suite available:
- Microsoft Office 2010 for Windows.
When basic authentication is disabled, Outlook clients using basic authentication will stop connecting with Microsoft Exchange Online to send and receive email messages. Users can access their NHSmail mailbox via Outlook Web Access if required.
Enabling MAPI over HTTP.
Make sure that users in your organisation with Office Outlook desktop clients for Windows and using RPC over HTTP are updated to use MAPI over HTTP.
Step 1: Run Windows update and confirm Office applications are updated by having the most recent cumulative updated. Your Office should have at least the currently recommended minimum installation of Outlook updates installed for connecting to Exchange Online that uses MAPI over HTTP. To verify the current list, see the following Microsoft Office article.
Step 2: Additionally, you may have to make sure that Outlook clients are not using a registry key to disable MAPI over HTTP. To confirm this, follow the below steps to check and change the registry value:
1. Exit Outlook.
2. Open Registry Editor by using one of the following procedures, as appropriate for your version of Windows:
a. Windows 10, Windows 8.1, and Windows 8: Press Windows Key + R to pen a Run dialog box. Type exe and then press OK.
b. Windows 7: Click Start, type exe in the search box, and then press Enter.
3. Locate and select the following key in the registry:
HKEY_CURRENT_USER\Software\Microsoft\Exchange
4. Right click MapiHttpDisabled and then click on Modify.
5. Change the Value data to 0 and then click OK.
6. Close Registry Editor.
7. Start Outlook.
Checking if Outlook is using RPC or MAPI over HTTP.
To confirm if registry changes were successful, follow the below steps to identify Outlook’s connection type:
1. Start Outlook.
2. Press and hold Ctrl button, then do right click on the Outlook icon in the task bar at the bottom right corner of the screen and select Connection Status.
3. Find Protocol column in the Outlook Connection Status screen.
a. If the protocol type is HTTP, it means the client is already using MAPI over HTTP to connect to Exchange Online.
b. If the protocol type is RPC/HTTP, it means the client is still using RPC over HTTP to connect to Exchange Online.
| Last Reviewed Date | 13/03/2023 |
