If you're wondering how to backup Yahoo emails to a USB flash drive or external hard disk, there are a couple of ways to do it. The manual method involves configuring your Yahoo account in an email client like Outlook using IMAP and then exporting the mailbox to a PST file, which can later be copied to your USB device. However, this process takes time, requires Outlook installation, and may not be ideal for users with large mailboxes.

I found an easier approach using the SysTools Yahoo Backup Tool. It lets you sign in to your Yahoo account, choose formats such as PST, MBOX, EML, PDF, or MSG, and directly save the backup to a connected USB flash drive or external hard drive. The software preserves folder hierarchy, attachments, and email metadata while also offering date filters and incremental backup options. For anyone looking to create a secure offline copy of Yahoo emails without complicated setup, this method is much more convenient and reliable.