For this question, I’d recommend BitRecover PST to MBOX Converter because the key requirement is exporting PST emails to MBOX with attachments intact. It supports bulk PST-to-MBOX conversion and preserves email headers, formatting, folder hierarchy, attachments, images, signatures and hyperlinks.
It also works without Outlook, so you can load PST files directly from local storage. Both ANSI and Unicode PST files are supported, along with large/oversized PST files and password-protected PSTs. A built-in Recovery Mode is available for damaged PST files.
For selective conversion, you can choose individual folders or apply filters such as date, sender, recipient and subject. You can also create separate MBOX files for different PST sources and select your own destination location.
The tool works offline, which is useful when the PST contains confidential mailbox data. The resulting MBOX files can then be opened with clients such as Thunderbird, Apple Mail, Eudora, SeaMonkey and other MBOX-compatible applications.
