Run the "Mac Gmail Backup" Software on the Mac machine.
Enter username & password of Gmail Account.
Click on Login Button
On the next screen, By default the file format will be selected as "EML" as shown below:
Select the destination location in which you want to keep the backup in local computer machine. Click on the "Browse"
The selected path will be shown as follows in the software user interface, as follows:
Click on Apply Filters, and choose the specific filters
Click on Start and the software will start running
A screen will appear Download Completed Successfully. Click OK
Downloaded Files will be viewed at specified location