Mail Contact list

Hello exrobotguy,

We're not sure that will work in the way you are attempting, but the Mac Mail app pulls your contact info from the Contacts app, and that is saved in your user library.

~/Library/Application Support/AddressBook/

If you want Mail specific items located in the system Mail/V'x numbered folders, we must warn you, playing in these Mail folders can cause your Mail to stop working. Make sure you have a backup before making any changes: How to back up your Mac - Official Apple Support

Also, you can create lists inside of Contacts, which is the way this should be done. We have groups that Mac Mail pulls up from the Mac Contacts app: Create and change lists in Contacts on Mac - Apple Support

Thanks.

Hello exrobotguy,

We would like to see how we can help you with your contacts. All contacts added from an outside source are located in the Contacts app. For more information visit: Add contacts from iCloud, Google, and more to Contacts on Mac - Apple Support

"Choose your default contacts account

If you use more than one account in Contacts, new contacts are added to the default account. You can choose the default account.

1. In the Contacts app  on your Mac, choose Contacts > Settings, then click General.
2. Click the Default Account pop-up menu (shown only if you use more than one account), then choose an account."

Cheers!

The Mail app is located in the Applications folder. Why do you need to where the contact list is stored?