Does not work.

Outlook.Application and Outlook._Application are both interfaces. And I want to use them as a class in my program (I don’t know how they made that work).

I wanted to extend Outlook.Application and add a simple method to create a new email. But that does not work since you have to implement a bunch of methods which I hardly understand.

Thank Microsoft for creating extension methods, so here is my solution:

using System;
using Outlook = Microsoft.Office.Interop.Outlook;

namespace SendToExtended
{
	static class OutlookExtensions
	{
		///

		/// Creates and returns an Microsoft Outlook MailItem
		/// 

		///
an instantiated Outlook application
		/// A new MailItem object
		public static Outlook.MailItem CreateMailItem(this Outlook.Application outlook)
		{
			if (outlook == null)
				throw new ArgumentException("outlook parameter cannot be null");

			return (Outlook.MailItem)outlook.CreateItem(Outlook.OlItemType.olMailItem);
		}
	}
}