Microsoft Outlook - Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.
PDFShift - Convert any HTML documents to high-fidelity PDF using a single POST request
Thunderbird - Thunderbird is a free email application that's easy to set up and customize - and it's loaded with great features!
DocRaptor - As the only API powered by the Prince HTML-to-PDF engine, DocRaptor provides the best support for complex PDFs with powerful support for headers, page breaks, page numbers, flexbox, watermarks, accessible PDFs, and much more
Front - multi-channel inbox service for collaborative teams
PDFCrowd - Pdfcrowd is a Web/HTML to PDF online service. Convert HTML to PDF online in the browser or in your PHP, Python, Ruby, .NET, Java apps via the REST API.