I need to archive data from several Outlook PST files and am considering converting the mailbox into formats that can be accessed without depending on Microsoft Outlook. MBOX would be useful for email-based archives, while PDF could be helpful for records that need to be searched or shared outside an email application.

The PST files contain a mixture of emails, attachments, contacts, calendars, and custom folders. I do not want to simply export everything blindly because a large portion of the mailbox is old or irrelevant. Ideally, I would like to preview the PST contents first, select the folders I actually need, and apply a date range to reduce the amount of unnecessary data.

I found SysInfo PST Converter while looking into this. The product information states that it can convert PST and OST data into multiple formats, including MBOX, EML, MSG, PDF, CSV, PNG, JSON, DOCX, VCF, and ICS. It also supports selective folder and date-range conversion, duplicate email removal, attachment handling, and preservation of the original folder hierarchy.

The duplicate-removal feature is particularly interesting because some of my PST archives contain repeated messages. However, I would want to make sure that legitimate emails with similar subjects are not incorrectly treated as duplicates. I am also interested in how attachments should be handled when producing PDF or other output formats. The software documentation mentions options for exporting attachments separately, merging them, or excluding them depending on the required output.

For anyone who has worked with PST archives for long-term storage, would you recommend converting the entire mailbox or first separating important folders and date ranges? Also, what should be checked after conversion to confirm that the resulting MBOX or PDF archive is complete?

I am particularly interested in experiences with large PST files, batch processing, folder hierarchy preservation, and maintaining email metadata. I want to keep the original PST files as a backup and verify the converted archive before considering the migration complete.