SOLVED: Can't Send Mail from Hotmail/Outlook.com (Exchange) in macOS Mail App with 2FA/App Password - Posting as Question to Share Solution

Hello everyone,

Since all the threads I found on this topic seem to have been locked with no proper answer, I am posting this as a question just to get the solution out there for others who might be struggling.

I've finally found a solution after hours of frustration trying to set up my Hotmail/Outlook.com email account (using the Microsoft Exchange option) in the default Mail app on macOS (I'm on 15.5, but this should apply broadly).

I was able to receive emails, but sending always resulted in an error. This is a common issue with Microsoft accounts that have Two-Factor Authentication (2FA) enabled, and Microsoft's documentation on this for Apple Mail is, frankly, lacking.

If you're experiencing similar issues, give these steps a try:

My Solution (Tested on macOS 15.5 Mail App):

1. Remove the Existing Account:
   • Open the Mail app on your Mac.
   • From the top menu bar, go to Mail > Settings (or Preferences on older macOS versions). You can also use the keyboard shortcut Command + , (comma).
   • Click on Accounts in the toolbar.
   • In the left sidebar, select the Microsoft Exchange email account that's giving you trouble.
   • Click the minus sign (—) at the bottom to remove the account. Confirm the removal when prompted.
2. Add the Account Fresh:
   • Still in the Accounts window, click the plus sign (+) to add a new account.
   • From the "Choose a Mail account provider..." list, select Microsoft Exchange. Click Continue.
   • Enter your Name and your full Email Address (e.g., ******@hotmail.com or ******@outlook.com). Click Sign In.
   • A web browser popup will appear, prompting you to "Sign in to your Exchange account using Microsoft?". Click Sign In within that popup.
   • You will be redirected to Microsoft's login page in your web browser. Log in with your regular Microsoft account password and complete your 2FA/Passkey verification as you normally would. Once authenticated, the browser window should close, and control will return to the Mail app.
   • You should now be able to receive emails into this newly added account. Confirm this before proceeding. However, sending emails will likely still fail.
3. Generate a Microsoft App Password:
   • Open your web browser and go to the Microsoft account security page: https://account.live.com/proofs/Manage/additional
   • Scroll down the page content until you find a section titled "App passwords."
   • Click on "Create a new app password." A 16-character password will be generated. Copy this password immediately. (You won't see it again once you leave the page).
4. Enter the App Password in macOS Mail Settings:
   • Go back to the Mail app.
   • Again, go to Mail > Settings (or Preferences) > Accounts.
   • In the left sidebar, select your Microsoft Exchange email account.
   • Click on the Server Settings tab.
   • At the top of this tab, you should see your "User Name" and a "Password" field. This password field might currently be empty or contain dots from a previous attempt. (For me, it was empties because of the login method used) In this password field, paste the newly created Microsoft App Password. (This handles the general account authentication, which can affect outgoing).
   • Important: Further down this "Server Settings" tab, ensure the checkbox for "Automatically manage connection settings" is checked.
   • Focus on the "Outgoing Mail Account" section. Select the Exchange (Exchange) option, or however you named it when adding your account. It most likely is already set to that, but when you use the same email for iCloud, I noticed it defaulting to iCloud on recent macOS versions.
5. Sync and Restart Mail App:
   • Close the Mail Settings window.
   • In the Mail app's left sidebar, Right-click on your Microsoft Exchange email account (the one you just configured).
   • From the contextual menu, click "Synchronize Account."
   • Finally, quit the Mail app completely (Command + Q or Mail > Quit Mail).
   • Reopen the Mail app. After following these steps, your sending issues should be resolved. It's frustrating that something this common requires so much troubleshooting, but I hope this helps anyone else running into the same problem. I never had a good experience with Microsoft and I am confident that I never will, hope this helps anyone.