I would like to suggest you can also try Mailsbackup Yahoo Backup Software to backup Yahoo Mails to hard drive by saving Yahoo emails into various file formats. It is a straightforward solution for users which allows user to save multiple Yahoo emails to computer at once without losing any data.Directly Import Yahoo Mails to Gmail, G Suite, Outlook.com, Thunderbird, Lotus Notes, Windows Live Mail, Exchange Server, IBM Verse, Amazon WorkMail, etc. It Supports to all Outlook Versions i.e. Outlook 2019, 2016, 2013, 2010, 2007, 2003, etc. You can also test the FREE Demo edition which is available for users. This allows user to backup 25 items from Yahoo mailbox folders to selected saving format.

Check for more details at: Yahoo Backup Software