Microsoft recently released an update to Outlook 2016 called Direct Connect to Office 365.

This update is causing connectivity problems for some users to our Hosted Exchange service.

Symptoms involve the inability to send email, sent email being returned with the sending address showing as a long outlook.com address or the inability for Outlook to open its folders due to a login error.

To fix the issue please do one of the following...

1. Download the attached registry file and double-click it to have it add the two registry entries needed to prevent this behavior. (Recommended)

2. Follow the instructions below to manually add the registry entries yourself...

Manually Add the Registry Entries

1. Close Outlook
2. Right click on the Start menu and click Run
3. Type regedit in the available space and click Enter (or click Start and type regedit)
4. Open Registry Editor (if prompted, click OK to allow it to run)
5. On the left side, expand HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\16.0\Outlook\Autodiscover
6. Right-click the Autodiscover key and click New > DWORD (32-bit) Value
7. Type in ExcludeExplicitO365Endpoint for the value name and then enter the value as 1
8. On the left side, expand HKEY_CURRENT_USER\SOFTWARE\Policies\Microsoft\Office\16.0\Outlook\Autodiscover
9. Right-click the Autodiscover key and click New > DWORD (32-bit) Value
10. Type in ExcludeExplicitO365Endpoint for the value name and then enter the value as 1
11. Start Outlook and see if it connects normally

If Outlook continues to exhibit issues, you will need to create a new Outlook profile and have it sync with our services.

Other Articles