If your client applications are unable to use Exchange Autodiscover to retrieve configuration information from Exchange Online, please follow the troubleshooting steps below.
The first place that a client application will look for autodiscover information is the Exchange Server Client Access Server (CAS) Service Connection Point (SCP) object in Active Directory. The SCP object will direct your client applications to your local CAS servers instead of Exchage Online. For more information on SCP objects, see our Service Connection Points article.
After checking SCP, the client application will first try to find an autodiscover file at the following address (substituting your domain name):
If you have a web server configured that will respond with this file, it can cause autodiscover to fail.
The second URL that will be tested is (again, substituting your domain name):
If you have an A record configured for this hostname, you will need to remove it from DNS. If CDS hosts your DNS with UltraDNS, you may submit a ticket to CDS Customer Care to have this record removed.
In most cases, you will have a CNAME record directing clients to
autodiscover.outlook.com instead. This is correct.
Finally, most client applications will attempt to use an SRV record to locate autodiscover information. This form of Exchange Autodiscover is not support in Exchange Online.
More information on DNS changes required for Exchange Online can be found in the DNS guide.
You can use Outlook's Test E-mail AutoConfiguration… to test what your Outlook client application will see when using autodiscover. To do so, hold the
Ctrl key and right-click on the Outlook icon in the notification area of the taskbar (commonly known as the “system tray”). Click on Test E-mail AutoConfiguration….
Enter your e-mail address and password and uncheck both Use Guessmart and Secure Guessmart Authentication. Now click on the Test button. When the test completes, you can check the Log tab to see what parts of autodiscover failed and succeeded.
If your test fails, and you would like additional troubleshooting assistance, please take screenshots of the Log tab (it cannot be copied and pasted) and send them to CDS Customer Care.
You can also perform some command line testing by using nslookup.
This should return some variant of “autodiscover.outlook.com”:
You will also need to check to see if Outlook is finding an SCP object. To verify your SCP objects have either been removed or modified to direct client applications to CDS, please review our article on Service Connection Points.
You can utilize the Microsoft Remote Connectivity Analyzer to test autodiscover from outside of your local network.
Start by choosing either Exchange ActiveSync Autodiscover (for mobile devices) or Outlook Autodiscover (desktops and laptops) from the Exchange Server tab. Click on the Next button.
Enter your e-mail address, your UPN (most likely your e-mail address), and your password. Enter the verification code, and click on the Perform Test button.
Your results page will be displayed. If you receive anything other than a success, you can expand the Test Steps section to see where the test failed. Common failures are entering the wrong e-mail address and password or having an autodiscover A record in your domain that needs to be removed.
If the test failed, and you would like further assistance with troubleshooting, please download a copy of your report (using the icon in the top-right) and send it to CDS Customer Care.
For further information on how your DNS should be configured, please see the DNS guide.