Mac Mail backup steps
STEP 1:
Open Apple Mail. Select "Mailbox" on the top toolbar. Then click on "New Mailbox" in the display menu.
STEP 2:
Select "On My Mac" from the "Location" dropdown menu. Choose a name for your new mailbox, such as "BYUI Backup."
STEP 3:
Highlight and drag the e-mails you wish to save into the new mailbox you just created. Then, you are done.

