For months some of our customers have been experiencing abnormalities within their outlook clients that have been causing major headaches for all. We had to get Microsoft involved in which we have been sending lot’s of log files with no resolution in site. Upon further investigation internally we were able to dig into the log files in outlook. Since Exchange 2007 Microsoft has had a function called AutoDiscover which helped end users easily configure their email clients and over time other vendors have adopted the same methods to deal with email services.

The following is an example of the error message below.

We got an unexpected Autodiscover response.

We can see that your mailbox is in Office 365. However, Autodiscover service seems to have configuration issues that prevent Outlook to connect Office 365. An intermediate web server at http://domain.com/Autodiscover/Autodiscover.xml is interfering with AutoDiscover service and responding with incomplete data.

Your administrator need to either remove or correct the AutoDiscover component from https://domain.com/Autodiscover/Autodiscover.xml

To work around this issue if your administrator can’t resolve the above soon, please take the following action:

Create an Outlook registry key to exclude the HTTPS root domain. For more information about how to do this, see the following Microsoft Knowledge Base article: 2212902

Important Excluding the HTTPS root domain is not a long-term solution for this issue. This workaround is provided as immediate relief for it. As soon as your administrator resolves the above Autodiscover issue, the Outlook registry key must be removed.

The easiest way to reproduce the error message above is to launch Outlook as Administrator by right clicking on the app and executing it. Once Outlook is opened and running hold the the CTRL key and right click the Outlook mail icon in the task bar and select test autoconfiguration.

With all of that said and going back to where other vendors have adopted the Autodiscover method mentioned above her in lies the issue. Most of the world is running their wordpress , joomla, drupal, blogs etc on hosting services which use either cPanel or Plesk for their backends. Back in the old days when POP and IMAP used to the be standard mail protocols they ran on these hosted platforms. These services now have their own Autodiscover services they use for the legacy people who still use POP and IMAP emails aka AutoDiscover.xml. The cPanel Autodiscover service runs by default and can interfere with services like Exchange online O365 when Outlook tries to validate it’s own configuration.

The Solution:

Login into your cPanel server and make sure that email routing is set to Remote Mail Exchanger which apparently turns the local service off on your webserver.

Essentially when email routing is not set to Remote Mail Exchanger it causes a black hole experience for Microsoft Services and so the pain starts. Always ask your web administrator to verify your web hosting settings are correctly set to prevent these potential issues from ruining your days.

We hope this can help others out there that may be scratching their heads with similar Outlook issues.