Follow the steps to understand the Yahoo Backup Software
Run Yahoo Email Migration tool in your system.
Select Advance option for backup multiple Yahoo Mail or Yahoo Small Business Mail accounts at once.
Enter login details of Yahoo Mail account in the interface.
Backup Formats options of Yahoo mailbox to several file formats
Export selected items from Yahoo mailbox to other account with setting Filters.
Migrate Emails from Yahoo Mail to Gmail Migration Process Started.
Backup Process of Yahoo Small Business Mail account is successfully completed.