- Step 1: On your Mac, launch the Mail app and click the Mail menu.
- Step 2: Select the Preferences option from the pull-down list.
- Step 3: In the Internet Accounts window, select your email account from the left-side panel.
- Step 4: Alternatively, you can open the Internet Accounts window by selecting System Preferences from the Apple menu and choosing Internet Accounts in the System Preferences window.
- Step 5: After selecting your email account, click the Remove icon (Minus symbol) at the bottom-left corner of the window.
- Step 6: Click the OK button to delete your email account.
- Step 7: Once you have deleted your Outlook email account, restart your Mac.
- Step 8: Launch the Mail app and re-add your Outlook account by manually configuring the server settings.
- Step 9: Make sure to turn off the 2-step verification for your Outlook account before adding it in the Mail app.
- Step 10: If the problem persists, delete the Offline Mail Cache folder on your Mac.
- Step 11: It will fix the account verification problem.