The article describes the issues that are related to the absence, improper configuration or resolution of CNAME record used for autodiscover service. The Autodiscover service provides access to Microsoft Exchange features such as: Autoconfiguration of profile, the Offline Address Book (OAB), Free/Busy Information, Out-of-Office assistant, Sharing Invitations, Auto-mapping of Shared Mailboxes, and is necessary for using Public folders in Exchange 2013 and later.

Autodiscover is available for Outlook clients 2007 and newer, and is required to configure an Exchange mailbox in Outlook 2016 and higher.  Similarly, Outlook for Mac 2011 and higher support Autodiscover, and require it to configure an Exchange mailbox in Outlook for Mac 2016 and higher.  For more information about this service refer to a Knowledge Base article on What Is An Autodiscover Record And Why Do I Need It?

Below are the symptoms that may indicate the problem with autodiscover process:

If you experience such issues, follow the suggested troubleshooting steps and read the information about autodiscover resolution process to know more about the root cause of the issue:

Read the symptoms description.

Outlook 2016/2019 cannot connect to the mailbox

When using the automatic configuration option to configure an Outlook profile, you may face the following error.

We are having trouble connecting to your account. Verify the settings below and make changes if necessary.

In most cases, this is caused by improper autodiscover resolution. Other causes are described in a Knowledge Base article on Why Can't I Connect My Outlook 2016/2019 To Exchange.

If autodiscover resolution gets corrupted or the corresponding CNAME record is erased when the profile is already configured, you will experience Send/Recieve errors and the Outlook profile won't sync.

Free/Busy information in your calendar is not available

If your account is hosted on the Exchange server and the Free/Busy information couldn't be retrieved in Outlook 2007/2010/2013 it is displayed as slash marks (\).

This can be caused by autodiscover, for other reasons read the Knowledge Base article on Why Is Free/Busy Information Unavailable In Outlook 2007/2010/2013?

Out of Office issues in Outlook

If you see the prompt below trying to set up Out of Office in Outlook, this is autodiscover related issue.

Your automatic reply settings cannot be displayed because the server is currently unavailable. Try again later.

Read the Knowledge Base article on How Do I Set Up Out Of Office Assistant? once the problem with autodiscover is resolved.

Offline Address Book synchronization issues

If your Outlook cannot pull current Offline Address Book from Exchange server, the issue can be resolved as described in the Knowledge Base article on Problems With Offline Address Book.

Sharing invitation does not work

If you see the prompt below when you try to send the invitation, that means that autodiscover does not resolve correctly.

Error while preparing to send sharing message.

For more information about sharing Calendars, Contacts, etc via Sharing Invitation read the Knowledge Base article on How Do I Share (Let Others See) My Outlook Folders (Inbox, Contacts, Calendar etc.)?

Shared mailbox auto-mapping does not work

If a user has full access permissions to another mailbox and it does not show automatically on Navigation Pane in Outlook application, you need to check how autodiscover resolves on the affected PC. For more information about auto-mapping read the Knowledge Base article on How Does Mailbox Auto-Mapping Feature Work in Exchange 2010/2013?

Note: Auto-mapping feature only takes effect when permissions are assigned against individual accounts, not distribution lists. That may be useful for Exchange users who do not want mailbox to appear automatically in Outlook, but still want to have full access to it and auto-mapping feature enabled. This can be used as an easy workaround to assign full access permissions to mailbox for group of people who will not use mailbox all the time, but still need full access permissions to it.  Automapping can also be disabled by our Level 2 team.

Public Folders are not accessible in Exchange 2013/2016/2019

Starting from Exchange 2013 Public Folder feature requires the presence of autodiscover record for a domain name for the email address you use to connect Outlook to the mailbox.  In case record is absent or resolves incorrectly the user won't see the Public Folders which admin made accessible for the user. For more information about Public Folders read the Knowledge Base article on Public Folders In Exchange 2013/2016/2019.

Read the information about autodiscover resolution and troubleshooting process.

Autodiscover resolution

Important: the issues above can happen due to a different root cause, however the absence of autodiscover record is the first suggestion to check.

In case autodiscover record is properly configured via your DNS hosting provider, there are no typos and mistakes, there can be a problem with the resolution of the record when Outlook fails to find the server autodiscover points to. Below are the steps Outlook performs when tries to find the autodiscover server:

  1. Check for O365 as a priority (only applies to Outlook 2016 version 16.0.6741.2017 and later versions)
    Outlook uses a set of methods to determine whether the provided user account comes from Office 365.
    If Outlook falsely determines that you are an O365 user, an attempt is made to retrieve the Autodiscover from the known O365 endpoints. A user might experience various issues described in our Knowledge Base article How To Fix The Credential Prompt Error In Outlook For Office 365 And Office Apps Users.
  2. SCP lookup 
    Outlook gets information from Active Directory (on-premises Exchange server). 
    If the record cannot be obtained from local domain, the SCP lookup fails.
  3. HTTPS root domain query
    Outlook, which is not connected to domain, uses the domain name part of SMTP address for this query:
  4. HTTPS Autodiscover domain query
    In case HTTPS root domain query fails, the lookup of is happening.
    Note: if your website stores XML file mentioned in step 3 or 4, the autodiscover process will fail. Contact your Web developer to remove the page from the site, so that the response of the links will be, for example, 404 Page not found.
  5. HTTP redirect method
    This step lets the Outlook find the Intermedia auodiscover server. In case correct DNS record is configured for your domain name, Outlook will successfully finish autodiscover process.

Also, the value of autodiscover record can be kept in your computer's OS cache or in a local hosts file, which was formerly used for resolution of IP addresses to domain names on user's machines.

After a mailbox profile is created, the mail client will still need to automatically connect to the Autodiscover service under the following conditions:

  • Every time the application starts
  • At certain intervals in the background
  • Any time the client's connection to an Exchange server fails
  • When using a service which requires Autodisover to function, such as the Offline Address Book, Out of Office Assistant, Free/Busy Information, Public Folders, or accessing shared mailbox data.


Follow the steps below to resolve the autodiscover related issues.

  1. Make sure you have correct CNAME record configured for autodiscover feature. Follow the Knowledge Base article on What Is An Autodiscover Record And Why Do I Need It? to have proper instructions.
  2. Clear DNS cache on your PC or Mac.
    • On PC: open Command prompt and type in ipconfig /flushdns. Execute the command.
    • On MAC OS X Yosemite: open the Terminal and type in  sudo killall -HUP mDNSResponder. Execute the command.

  3. Run Test E-mail AutoConfiguration tool in Outlook to review on what step Outlook fails to connect. This provides a good measure of how the user's workstation or network is resolving autodiscover. If you do not see the failed step in the log,  contact Support and provide us the results, so that we could further assist you.
  4. Run the  Microsoft Remote Connectivity Analyzer, choosing Outlook Autodiscover radio button under Microsoft Office Outlook Connectivity Tests section. This test provides information on how your autodiscover resolves globally. Follow the instructions and provide Support with results of the test.
  5. If the Autodiscover for your domain resolves correctly, but there is one machine affected where you cannot setup profile automatically or features that depend on autodiscover does not work, modify the hosts file following the Knowledge Base article on How Do I Find And Modify Entries In The HOSTS File?
  6. If the Autodiscover resolves using your local ActiveDirectory values and does not find the values kept by the DNS hosting provider, follow the steps described in the article Why Can't I Connect My Outlook 2016/2019 To Exchange to use HTTP redirect method and skip all initial lookups.
    Note: the article provided in this step helps to resolve the issue of incorrect DNS resolution for all working stations included to your domain in case you were utilizing on-premises Exchange prior to migration of your mailboxes to Intermedia.
  7. If the test shows that autodiscover resolution fails due to a presence of an XML file on your website, contact your web developer to remove the files. As a temporary workaround you can use the steps described in the article Why Can't I Connect My Outlook 2016/2019 To Exchange to use HTTP redirect method and skip all initial Autodiscover resolution steps.
  8. If you have an existing Outlook profile and you utilize Outlook 2010 or 2013, which were set up manually or with Outlook Profile Helper, in Outlook navigate to File > Account Settings > Account Settings > Change > More Settings > Connection > Exchange Proxy setting and make the following changes:
    • Switch Basic Authentication to NTML Authentication
    • Check Only connect to proxy servers that have this principal name in their certificate check box
    • Type, where XXX depends on your proxy server information.
      Important: to protect your account information we cannot publish your Server names in public Knowledge Base. You can find your Exchange Proxy Server by navigating to HostPilot > Home >Exchange Servers and Settings > Exchange Proxy Server
    Then you will get a security prompt, check the box Don’t ask me about this website again and then click Allow. Note: If your autodiscover record is incorrect, then these steps may be reverted some time later by the autodiscover process in Outlook. Therefore, it is best to make sure that your global autodiscover record is correct, as this may only be a temporary fix.
  9. Outlook 2016, which only can be configured when there is an existing autodiscover record for your domain, may take too long to connect to the mailbox, to resolve this refer to the known issue #2 in the Knowledge Base article on How Do I Configure Outlook 2016/2019 To Connect To Exchange.
  10. When Outlook implements HTTPS root domain query it can fail due to incorrect SSL installed on your website. For more information read the Knowledge Base article on Autodiscover Security Certificate Error.