I'm planning to move an old collection of Outlook MSG emails into an MBOX-based mail system and want to avoid unnecessary intermediate conversions.
I've been looking at the MacSonik MSG Converter Tool  because it supports direct MSG-to-MBOX conversion and can also migrate MSG data to clients such as Thunderbird and other email platforms.
The archive isn't limited to ordinary emails either. There are attachments, contacts, calendars, tasks, notes, and meetings that I may need to retain. According to the tool's features, it can convert these MSG components while maintaining the folder hierarchy.
The preview option is another feature I'd probably use before starting a large migration. Being able to check the email content and attachments first should make it easier to catch problems early.
Has anyone here used MacSonik for MSG-to-MBOX migration? I'd especially like to know how it performs with larger MSG collections.