My Exchange Email Won't Connect Microsoft Outlook Mac


If you're using Outlook to access your Office 365 email account or another Exchange-based email account, and you're having problems, we want to get you back to sending and receiving email as quickly as possible.

If you successfully connected to the account before, try to connect to it from another Exchange application, such as Outlook Web App. You can also check the status of the Exchange server by contacting your Exchange server administrator. Cause: Your Exchange account requires you to log on by using an encrypted channel. Cause: Outlook is not connected to the server that is running Microsoft Exchange Server. Solution: Check your Microsoft Exchange server connection. On the Tools menu, click Accounts. Look at the Exchange account in the left pane. If there is a problem with the connection, the indicator icon will be orange. Apple Mail is the default email client that comes with every Mac using OS X 10. Apple Calendar allows you to pull in info from other calendars, too, such as Google Calendar, Microsoft Exchange, Yahoo, and any calendar that uses CalDAV. I use outlook for Mac on my computer. This ensures that iMessages sync across all devices that use that Apple ID. It is very possible that your company is running an Exchange Server that is not compatible with Outlook for Mac 2016. Check with your company's help desk to find out if this is indeed the issue and if so how you can reinstall Outlook 2011.


If you're looking for help with Outlook.com, check out Help for Outlook.com. > If you're looking for help with Outlook for Mac, check out Outlook 2016 for Mac Help.

Let us fix your Outlook connection problems for you

We can diagnose and fix several common Outlook connectivity issues for you. If our automated tool can't fix your issue, or you'd like to fix it yourself, see the next section.

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Fix software update and profile issues

Out-of-date software and corrupted Outlook profiles are two of the most common issues that can prevent you from sending and receiving email. If you're an admin with multiple users reporting problems, you also should check for service issues with Office 365.

My Exchange Email Won't Connect Microsoft Outlook Mac Free

Common Outlook fixes

Run Windows UpdateIf your Outlook client software or Windows operating system software is out of date, you might have problems sending and receiving email. For Windows Update instructions, see Windows Update: FAQ
Repair your Outlook profileAn Outlook profile is a set of configuration information that includes your user name, password, and file storage location. To repair your Outlook profile, see Fix your Outlook email connection by repairing your profile.
Check for service issuesAdmin only: If more than one person in your organization is experiencing email problems in Office 365, it could be due to a problem with the service. Go to the Office 365 service health dashboard page (admin sign in required), and check the status of the services under Exchange Online.


When you try to create an Outlook profile or connect to a Microsoft Office 365 mailbox, you're continually prompted for credentials while the client displays a 'trying to connect...' message. If you cancel the credentials prompt, you receive the following error message:


The connection to Microsoft Exchange is unavailable. Outlook must be online or connected to complete this action.


This issue can occur if the Logon network security settingon the Security tab of the Microsoft Exchange dialog box is set to a value other than Anonymous Authentication.



Microsoft Outlook 2016 and some recent builds of Outlook 2013 are not affected by this issue. Those versions have been updated to prevent the problem that is described in the 'Symptoms' section. These versions have the Logon network security setting disabled or removed from the Microsoft Exchange email account settings.

For newer versions of Outlook

You may be an Office 365 customer who is experiencing the error that is described in the 'Symptoms' section when you try to connect to an Exchange Online mailbox. You may also already be running newer versions of Outlook 2013 or Outlook 2016. If both conditions are true, we highly recommend that you use the Outlook keeps asking for my password diagnostic to troubleshoot issues in which Outlook continually prompts for a password.

This diagnostic does automated checks and returns possible solutions for you to use to try to fix any detected issues.

If you are connecting to an Exchange On-Premises mailbox, see the following articles for additional troubleshooting:


Additionally, you can view the following forum thread for common causes:

For affected versions of Outlook

If you have an older version of Outlook, change the Logon network security setting to Anonymous Authentication to fix this issue. To do this, follow these steps:

  1. Exit Outlook.

  2. Open Control Panel, and then do one of the following:

    • In Windows 10, Windows 8.1, or Windows 7, click Start, type control panel in the search box, and then press Enter.
    • In Windows 8, swipe in from the right side to open the charms, tap or click Search, and then type control panel in the search box. Or, type control panel at the Start screen, and then tap or click Control Panel in the search results.
  3. In Control Panel, locate and double-click Mail.

  4. Click Show Profiles, select your Outlook profile, and then click Properties.

  5. Click E-mail Accounts.

  6. Select your email account, and then click Change.

  7. In the Change Account dialog box, click More Settings.

  8. In the Microsoft Exchange dialog box, select the Security tab.

  9. On the Login network security list, select Anonymous Authentication, and then click OK.

  10. Click Next, click Finish, and then click Close on the Account Settings dialog box.

  11. Click Close on the Mail Setup dialog box, and then click OK to close the Mail control panel.

More Information

To locate and view the registry setting for Anonymous Authentication in the Outlook profile, follow these steps.


Modifying the Outlook profile by using the 'Profiles' registry path is not supported and may cause your Outlook profile to be in an unsupported state.


Follow the steps in this section carefully. Serious problems might occur if you modify the registry incorrectly. Before you access it, back up the registry for restoration in case problems occur.

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  1. Open Registry Editor. To do this, do one of the following:

    • In Windows 10, Windows 8.1, or Windows 8, press the Windows logo key+R to open the Run dialog box, type regedit.exe, and then click OK.
    • In Windows 7, click Start, type regedit in the Start Search box, and then press Enter. If you're prompted for an administrator password or for confirmation, type the password, or click Allow.
  2. Locate the following registry path, as appropriate for your version of Outlook:

    • For Outlook 2013


    • For Outlook 2010 and 2007

      HKEY_CURRENT_USERSoftwareMicrosoftWindows NTCurrentVersionWindows Messaging SubsystemProfiles

  3. Under this subkey, locate and expand the name of your Outlook profile.

  4. Under the profile, locate and expand the 9375CFF0413111d3B88A00104B2A6676 key.

  5. Under the 9375CFF0413111d3B88A00104B2A6676 key, you see a subkey for each account in your profile. Select the first subfolder (00000001), and then examine the data of the Account Name binary value by double-clicking the value. Repeat this process until you find the Account Name value that includes your SMTP address. For example, the Account Name value points to **[email protected]** under the 00000003 subkey.

  6. Under the 0000000x subkey, locate the Service UID binary value. It represent a GUID (for example, c3 d1 9a 7b 80 1b c4 4a 96 0a e5 b6 3b f9 7c 7e).

  7. Locate the subfolder in your profile that matches the GUID value that's identified in step 6 (for example, c3d19a7b801bc44a960ae5b63bf97c7e).

  8. Under the subkey that you found in step 7, examine the 01023d0d binary value. It represents a GUID (for example, 5f cf d5 f1 ba 5c 6f 45 b3 57 cc 5e 0d 16 94 58).

  9. Locate the subfolder in your profile that matches the GUID value that's identified in step 8 (for example, 5fcfd5f1ba5c6f45b357cc5e0d169458).

  10. Under the subkey that's found in step 9, examine the value of the 00036619 binary value. This value determines whether Outlook is using Anonymous Authentication.

    Binary: 00036619

    Data: 01 f0 00 80Anonymous Authentication

    Any other value represents an authentication method other than Anonymous.