Microsoft Exchange password not being recognised in Apple MacBook Calendar, but fine on iPhone

Thanks for getting back to us here in Communities, Kellloggz.

It appears you have Automatic set for your user name, make sure and confirm that the email address is the correct address for your account: Add or delete calendar accounts on Mac - Apple Support

"Add a calendar account

1. In the Calendar app  on your Mac, choose Calendar > Add Account.
2. Do one of the following:

• Select your calendar account provider, click Continue, then follow the onscreen instructions.
• If your calendar account provider isn’t listed, ask your provider for the information you need to enter. 
• Choose Other CalDAV Account, click the Account Type pop-up menu, then choose an option based on the information you need to enter.
  • Automatic: Choose this option if you just need to enter your email address and password.
  • Manual: Choose this option if you need to enter your user name, password, and the server address.
• Advanced: Choose this option if you need to enter your user name, password, server address, server path and port number. You can also select checkboxes if you need to use SSL or Kerberos v5 authentication."

Are you using Keychain? Manage passwords using keychains on Mac - Apple Support

This article from Microsoft might also help if you have Two-Step verification: https://support.microsoft.com/en-us/account-billing/how-to-use-two-step-verification-with-your-microsoft-account-c7910146-672f-01e9-50a0-93b4585e7eb4

"Where you can't use security codes, use app passwords

Some apps (like the mail apps on some phones) or devices (like the Xbox 360) can't use regular security codes. If you see an “incorrect password” error on an app or device after you turn on two-step verification, but you’re sure your password was correct, that means you'll need an app password for that app or device.

App passwords are only available if you use two-step verification. If you don't have two-step verification turned on, you won't see the App passwords section on the Additional security options page.

Read about how to create and use app passwords in App passwords and two-step verification."

It wasn't mentioned, but are you able to log in with no issues to your Microsoft account?

Keep us updated.

Cheers!

Hello Kellloggz,

Welcome to Apple Support Communities!

If we understand your post correctly, the Calendar app on your MacBook keeps asking for the Microsoft Exchange email password even though you continue to put in the correct password it comes back saying it can't verify the username or password. We'd like to help!

Take a look at the steps below:

If your calendars are administered through Microsoft Exchange Server 2007 with Service Pack 1 or later (for example, through your workplace), you have a main Exchange calendar named Calendar in the Calendar app  on your Mac.

You can add calendars to your Exchange calendar account, but you won’t be able to see updated invitations or attendee responses for events in those calendars. Also, events in the additional calendars won’t be visible to delegates (people who share your calendar account) and won’t appear when users check your availability. Full calendar features are available only in your main Exchange calendar.

About using Exchange calendars on Mac

Let's also check if you have an app specific password. Follow the steps in the article below.

Sign in to apps with your Apple ID using app-specific passwords

Let us know if you have any questions.

Thank you for using Apple Support Communities.

Take care!

Thanks for the additional information, Kellloggz! From here, as you've went through some great steps already, we'd recommend looking at the following link: Exchange Account

Let us know if this helps. Regards.

Hi again Kellloggz,

Thanks for the follow-up info. Your time and feedback are greatly appreciated. Feel free to reach back out if you have any other questions, or run into any further trouble.

Take care and stay safe.