SysTools MBOX Converter vs Zamzar API

SysTools MBOX Converter has no write-up on Specifiction yet; its figures are above.

Zamzar API is a REST-based HTTP service for adding file conversion to mobile, web, or desktop applications. It supports more than 1,100 conversion types across documents, video, images, audio, eBooks, CAD, 3D, and compressed files. Files can come from a user's machine or be reachable through HTTP, FTP, SFTP, or Amazon S3. Zamzar says its cloud service can handle demand from one file to 10,000. Developers can use official Java, PHP, and Python SDKs, plus code samples for C#, cURL, Node.js, and other languages. The free Test plan costs nothing, requires no card, and includes 100 credits, a 1 MB maximum file size, one-day file storage, and a three-day support response. Paid plans start at $25 /month. Successful conversions use at least one credit, and unused monthly credits do not roll over. Zamzar describes the API as a conversion service, not a CDN; converted files should be retrieved through the API. Accounts include free sandbox testing subject to file-size and job-count limits.