I can't add an M365 email account to apple mail.

Hi @neil pbisports.com

Thank you for sharing your concerns. 

I understand that you are unable to access your M365 account via the Apple Mail app due to the “limit of attempts has been exceeded” message. Looks like this issue is triggered when Apple Mail makes repeated authentication attempts during account setup. Even if your M365/Exchange account works fine in a browser, Outlook, or other email clients, Microsoft’s security systems may temporarily block further sign‑ins from that device to prevent potential brute‑force attempts. 

To troubleshoot this issue, you could try to follow these steps: 

Sign in using another browser first 

Please stop attempting to add the account for at least 60 minutes. Avoid repeated retries during this time, as they may extend the lockout period. 

After waiting, open a web browser in private/incognito mode and log in to Outlook web app using your M365 email address and password. Complete any MFA prompts if applicable. This can help reset the session on Microsoft’s side. 

Clear old credentials on your Mac device 

Open Keychain Access. Search for your email address or the keywords “Exchange”, “Microsoft”, or “Office”. 

Delete any matching login or password items. 

This step helps prevent Apple Mail from reusing cached or invalid authentication tokens. 

Once completed, please try adding your M365 account again in Apple Mail and let me know if this resolves the issue. 

Please understand that our initial reply may not always immediately resolve the issue. However, with your help and more detailed information, we can work together to find a solution. 

Note: Please follow the steps in [our documentation] to enable e-mail notifications if you want to receive the related email notification for this thread. 

The error about exceeding the limit of attempts is coming from the Microsoft 365 side when Apple Mail repeatedly fails to authenticate the account. The account itself is fine, but the connection from Apple Mail is blocked until credentials are re-entered or the account is reconfigured.

Use these steps on the Apple device to restore access:

1. Re-enter credentials in Apple Mail
   1. When prompted in Apple Mail, choose Edit Settings and re-enter the Microsoft 365 username and password.
   2. If no prompt appears:
      • Open Settings.
      • Go to Apps > Mail > Mail Accounts.
      • Select the Microsoft 365/Exchange account and re-enter the login credentials.
2. If re-entering credentials does not work, remove and re-add the account
   1. Delete the Microsoft 365 account from Apple Mail:
      • Open Settings.
      • Tap Apps > Mail.
      • Tap Mail Accounts > Exchange.
      • Tap Delete Account at the bottom.
   2. Add the Microsoft 365 account back:
      • Open Settings.
      • Tap Apps > Mail.
      • Tap Mail Accounts > Add Account.
      • Choose Microsoft Exchange and sign in with the Microsoft 365 credentials.

If the password is not known or has changed, reset it first using the work or school password reset process described in Reset your work or school password using security info or, for GoDaddy-hosted Microsoft 365, via GoDaddy’s reset process.

If issues persist specifically with the iOS Mail app (Apple Mail on iPhone/iPad), contact Apple Support for Mail app issues, or the Microsoft 365 admin/technical support for work or school accounts.

References:

• Reconnecting your Microsoft 365 account to Apple Mail
• Set up an Outlook account on the iOS Mail app