Merge PST for Mac Software to easily perform this task with an easy mouse click. It supports both ANSI and UNICODE versions of PST files and merges multiple PST files in one PST file externally without any data loss. This software supports all Mac OS versions. You can download the free trial version software.

Pimcore is an open-source software platform used by more than 110 000 companies worldwide. It offers state-of-the-art digital asset management (DAM), product information management (PIM), master data management (MDM), digital experience management (DXP/CMS), multi-channel publishing, and digital commerce. Acclaimed by analysts at Gartner and Forrester, its customers include Fortune 100 companies such as Pepsi, Sony, and Audi. The company's headquarters are in Salzburg, Austria. 
Pimcore’s consolidated platform enables organizations to manage product information, digital assets, digital commerce, and web content in a consolidated setup, thus empowering them with a single ‘trusted view’ of information and delivering a superior product experience to their customers across multiple touchpoints.
What makes Pimcore a great open-source alternative to proprietary, closed-source software is its incredible flexibility, 100% API-driven architecture, composable technology, speed-to-market, plus the momentum of 150+ global solution partners. The Pimcore Platform™ is loved by developers, agencies, and enterprises. For more information, please visit pimcore.com.