Change default mail client mac to outlook without opening mail

You can change the default mail client on a Mac without opening Mail by using the following steps:

1. Go to the Apple menu and select "System Preferences".
2. Click on "Internet Accounts".
3. Select the account you want to change the default mail client for (e.g. iCloud, Exchange, etc.).
4. Click on the "Account Information" tab.
5. Click on the "Default Mail Reader" dropdown menu and select "Microsoft Outlook".

Alternatively, you can also use the Terminal app to change the default mail client. To do this:

1. Open the Terminal app on your Mac.
2. Type the following command and press Enter:

   defaults write com.apple.mail DefaultMailApp /Applications/Microsoft\ Outlook.app

   This will set Microsoft Outlook as the default mail client on your Mac.

Note: Make sure you have Microsoft Outlook installed on your Mac and that it is located in the /Applications folder. If you have a different version of Outlook installed, you may need to adjust the path accordingly.

Also, keep in mind that changing the default mail client will only affect new mail messages and not existing ones. If you want to change the default mail client for existing mail messages, you will need to open Mail and set the default mail client manually.