How Can I Move Emails from Multiple Webmail Accounts Without Losing Folder Structure?

I'm helping a small business move all their email data to a new platform, and we're dealing with several Gmail, Outlook, and Yahoo accounts. Initially, we tried exporting each mailbox manually, but it quickly became obvious that the process wasn't practical. Some exports missed folders, others duplicated emails, and managing multiple accounts one by one was taking far too long. We also wanted to keep the original folder hierarchy because employees were already familiar with the existing mailbox organization. Since these accounts contained years of customer conversations, invoices, and contracts, losing even a small amount of data wasn't acceptable.

While researching different solutions, I found DRS Softech Webmail Backup Tool. It seemed to fit our requirements because it supports backups from multiple IMAP-enabled services and exports data into formats like PST, MBOX, PDF, EML, and CSV. During testing, I liked the Date Filter for selective backups and the Remove Duplicate feature, which prevented unnecessary mailbox clutter. The software also preserved attachments, email headers, timestamps, and folder structure exactly as they existed on the server. Another useful feature was the option to skip previously migrated emails, making future incremental backups much faster.

After using the software for several mailboxes, I realized another advantage after working through multiple backup sessions. The Webmail Backup Software also supports direct migration to Gmail, Office 365, IMAP, and Google Workspace, making it useful not only for backup but also for complete email migration projects. The Split PST option helped us manage larger mailbox exports, and the standalone interface made deployment simple across different Windows systems. The demo version allowed us to verify the workflow before purchasing, which made the decision much easier. Has anyone else handled a similar multi-account migration? I'd be interested to hear what worked best for you.