Looking to convert maildir to mbox without losing folder hierarchy and email integrity has been quite challenging for me. I migrated from a Linux server where emails were stored in Maildir format, and now I need everything accessible in an MBOX-supported client like Thunderbird. While searching, I came across DRS Softech Maildir Converter Tool, which seems to handle folder hierarchy preservation and bulk conversion. https://www.drssoftech.com/blog/convert-maildir-to-mbox/