The site is entirely devoted to sending of mail from .NET with use System.Web.Mail . Contains the big number of articles and very detailed FAQ.

Complete FAQ for sending email in .NET with System.Web.Mail

If you develop web applications which use Enterprise Library that it is necessary to prepare it, but you will need to recompile the code .Just go into the Project Properties dialog for the Common project, and under Configuration Properties\Build, find the Conditional Compilation Properties property and remove ;USEWMI;USEEVENTLOG;USEPERFORMANCECOUNTER . Once you recompile, the  Enterprise Library will be ready for deployment.