Use Windows MBOX Duplicate Remover, please. Click delete MBOX File Duplicates Tool in
CubexSoft MBOX Duplicate Remover to quickly and without any data loss delete Thunderbird MBOX files from Windows. The process of removing this software from the MBOX Duplicate file only takes a few seconds. Single MBOX, file mode, and multiple MBOX files are the three methods available for Windows OS to remove duplicate MBOX files. This program is compatible with MBOX file email clients like Thunderbird, Apple Mail, Sec Monkey, Poco Mail, Eudora, Entourage, etc. Support is available for every version of Windows, including versions 11, 10, 8.1, 8, 7, XP, and Vista.