maximum number of Microsoft Exchange accounts has been added

Hi! The error appears because Outlook (classic for Windows) enforces a hard limit of 10 Microsoft Exchange accounts per profile, regardless of whether it’s a home or work setup. Once you reach that number, you cannot add more Exchange-based accounts (Microsoft 365, Outlook.com, or on-prem Exchange) in the same Outlook profile. If you’re seeing this error with fewer than 10 accounts, it may be due to a local policy or corruption in your Outlook profile.

To resolve this, first check how many Exchange accounts you already have under File > Account Settings > Account Settings > Email. If you’re at 10, you’ll need to either remove one or create a new profile (Control Panel > Mail > Show Profiles > Add), since each profile can host up to 10 Exchange accounts. If you’re below the limit but still blocked, recreating your profile usually clears the restriction. As an alternative, you can also use the new Outlook app or Outlook on the web, which doesn’t have this same account cap.

Dear Michael McFarland ,  

Thank you for reaching out with your question. I understand you are receiving an error message in Outlook that says, "The maximum number of Microsoft Exchange accounts has been added based on a policy set by your organization. For more information contact your administrator."  

Explanation of the Problem  

The error message you're seeing, "The maximum number of Microsoft Exchange accounts has been added based on a policy set by your organization," indicates that a policy, likely a Group Policy or a registry setting, is limiting the number of Exchange accounts you can add to your Outlook profile. The  cause is a registry key that limits the number of Exchange accounts. Outlook profiles can sometimes get corrupted or hold onto old data, contributing to this issue. Please kindly follow these steps to fox the issue   

Step 1: Check and Modify the Registry   

1. Open the Registry Editor:  
   • Press the Windows key + R to open the Run dialog box.  
   • Type regedit and press Enter.  
   • If prompted by User Account Control, click Yes.  
2. Navigate to the Correct Registry Key:  
   • In the Registry Editor, navigate to the following path. The exact path depends on your version of Outlook.  
   • For Outlook 2016, Outlook 2019, or Microsoft 365 Apps for business/enterprise: HKEY_CURRENT_USER\Software\Policies\Microsoft\office\16.0\outlook\profiles  
   • For Outlook 2013: HKEY_CURRENT_USER\Software\Policies\Microsoft\office\15.0\outlook\profiles  
3. Create or Modify the DWORD Value:  
   • In the profiles folder, look for a DWORD (32-bit) Value named MaxNumExchangeAccounts.  
   • If this value exists, double-click it and change the Value data to a higher number (e.g., 10, 20, or a value that is greater than the number of accounts you have).  
   • If the value does not exist, right-click in the empty space in the right pane, select New > DWORD (32-bit) Value, and name it MaxNumExchangeAccounts. Then, double-click it and set the Value data to your desired limit.  
4. Restart Outlook:  
   • Close the Registry Editor and restart Outlook. You should now be able to add a new Exchange account.  

Step 2: Create a New Outlook Profile (Alternative Solution)  

If the registry key modification doesn't work, the issue may be with your current Outlook profile. A new profile starts with a clean slate and can bypass the issue.  

1. Open the Mail Setup Dialog:  
   • Press the Windows key, type Control Panel, and press Enter.  
   • In the Control Panel, change the "View by" option to Large icons or Small icons.  
   • Click on Mail (Microsoft Outlook). This will open the Mail Setup window.  
2. Create a New Profile:  
   • In the Mail Setup window, click Show Profiles....  
   • Click Add... and give your new profile a name (e.g., "MyNewProfile").  
   • Follow the on-screen instructions to add your email accounts to this new profile.  
3. Set the New Profile as the Default:  
   • In the Mail Setup window, you can either select "Always use this profile" and choose your new profile from the dropdown, or you can select "Prompt for a profile to be used" to choose your profile each time you open Outlook.  

Step 3: Repair or Reinstall Office  

In rare cases, a corrupted Office installation can cause unexpected behavior.  

1. Repair Office:  
   • Press the Windows key + I to open Settings.  
   • Go to Apps > Apps & features.  
   • Find your Microsoft Office installation in the list, click on the three dots next to it, and select Modify.  
   • Choose Online Repair and follow the prompts. An Online Repair is more thorough and should fix most issues.  

Official Microsoft Links and Resources  

For additional guidance and official documentation, you can refer to the following Microsoft resources:  

• Microsoft Support Article on Adding an Account: Add an email account to Outlook for Windows - Microsoft Support  

If you require additional guidance or if the issue persists, please feel free to reply to this thread. If you found the answer helpful, we’d really appreciate it if you could click "Accept Answer" and kindly give it an upvote. Your feedback helps others in the community too!