Aspose.Email for .NET is a set of components allowing developers to easily implement email functionality within their ASP.NET Web applications, Web services, and Windows applications. It supports the Outlook PST, EML, MSG, and MHT formats. It allows developers to work with SMTP, POP, FTP, and MS Exchange servers. It supports mail merge, iCalendar, customized header and body, header information, embedded files, Twitter, and much more. It makes it easy to work with HTML or plain text email messages and their attachments.
TCRun is a tool written by software engineers in QA to help in writing, managing, and running automated test cases. The current version is written in C# for use on Windows, though other versions / platforms may be created later as necessary. It tries to make writing automated test cases as simple and painless as possible. It includes support for NUnit exceptions, logging (both test case specific and framwork/runtime), parameterized tests, test case resource files, and a validation framework. It can be used in mono, but is somewhat untested (it's actually built by mono, and it tests itself).