VSTO C#, OL2007

I want to remove the phrase "My Special Sentence" from every email after it
gets sent and appears in the Sent Items folder.

I started, finding the following code on the internet but being new to C#
and VSTO I have had some difficulties with syntax errors with it.

using Outlook = Microsoft.Office.Interop.Outlook;
defaultFolder =
this.Session.GetDefaultFolder(Outlook.OlDefaultFol ders.olFolderSentMail);
defaultFolder.Items.ItemAdd += new
Microsoft.Office.Interop.Outlook.ItemsEvents_ItemA ddEventHandler(SentItems_ItemAdd);

Can anyone help me with some code to remove the phrase "My Special Sentence"
from every email after it gets sent and appears in the Sent Items folder.

TIA