You can take the help of Yahoo Backup Software to backup your lost email to Hard drive ino multiple file format, this utility provide auto incremental backup solution in which user can set backup limit for specific email bacup,it is all-in-one Backup Utility to save backup of unlimited cloud-based applications easily, ou can also migrate Yahoo mail to Rediffmail, Outlook.com, Office 365, Windows Live Mail, Yahoo, Gmail, G Suite, Exchange Server, Lotus Notes, Thunderbird, Hosted Exchange Server, Zimbra and many more.
You can easily create backup with use of Yahoo Backup software and save them into multiple file format such as PST, MBOX, MSG, EML/EMLX/. you can search through google but i deeply guide you to try Yahoo Backup software.This software is one of the most valiant tools and has a friendly user interface by which it is easy to operate the software. So go ahead and download the software.
There are so many application on internet for creating yahoo backup but i would like to suggest you to try Yahoo Backup Application. It is one of the best application for creating yahoo backup. I read about this application that application create backup easily of your account in a few steps they require the password or username the tool is providing trial version and in this application you have an option to backup to PST, MSG, EML, EMLX, HTML, MBOX and MHTML file format if want to backup other formats.
Unpretentious and efficient solutions are available for taking yahoo backup. You can download this Cloud Email Backup Tool and convert or export all mailbox items from Yahoo to PST, EML, EMLX, MBOX, and MSG file format. You can advise this availability to others. For more information visit here: https://www.sametools.com/cloud/backup/