You can remove duplicate PST mailboxes with "SameTools Remove Outlook PST Duplicate." This software is professionally designed for removing duplicate PST files, which include copies of your emails, attachments, etc. Duplicate PST files are scanned and removed immediately, and do not require additional software, and also save your important data, as information loss can occur when using questionable Outlook PST duplication software. This tool allows a wide support for all Windows OS, including Windows 11, 10, 8.1, 8, 7, and also ranges of ANSI and UNICODE formats.