After evaluating many open source solutions for formats conversion and encounter with so many problems not only with implementations but also with the quality of the output files. We decided to use Aspose Email for .NET framework as part of our solution for the past four years and would like to share this review on this product.
Aspose Email for .NET allows us to manage message storage files such as Personal Storage Files (PST) & Offline Storage Files (OST). We can also use the API to transmit messages via a number of popular protocols like POP3, IMAP & SMTP or connect with Microsoft Exchange Server Exchange Web Services to send and receive emails with attachments. Integrating Aspose dll into c# is fairly easy. It does not cause any conflicts and works well as expected.
I highly recommend Aspose.Email for .NET. The company seems to be delivering constant updates and keeping in time with the rest of the technology world (by looking at their twitter feed and newsletters). But the biggest point is the time savings for my project, having just one set of APIs to relate to, makes this a money saver for me.