1. 打开VS2005.Net,New Project-->Other Project Types--> Extensibility--> Shared Add-in.
2.引用Micorsoft Outlook Object 12.0 library
3. 其它问题可以参考, http://www.cnblogs.com/dudu/articles/3891.html
4.如何获取用户当前选中的邮件呢?


Selection selection = applicationObject.Application.ActiveExplorer().Selection;
if (selection != null)
{
IEnumerator enumerator = selection.GetEnumerator();
while (enumerator.MoveNext())
{
MailItem mail = enumerator.Current as MailItem;
if (mail != null)
{
}
}
}
5.如何显示邮件内容呢?
this.webBrowser1.Navigate("about:blank");
this.webBrowser1.Document.Write(mail.HTMLBody);