After you have changed the set of fields, you need to provide a way for this form to be recognized (by a Microsoft Exchange client or by CDO) for the new, distinctive, type that it is. You do this by specifying and naming a new message class. You can give it any name you want, such as IPM.MyNote.
To set the message class, assign it to the Type property of the Message object. For example, this assignment occurs in Resolve.asp:
oNewMessage.Type = "IPM.Microsoft.ITG.NewClassifiedAd"
Before you make this assignment (for newly created objects), the Type field had a default setting of IPM.Note.
To have the Microsoft Exchange Client recognize a new message class, use the Microsoft Exchange Forms Manager to add it to the forms library. Then, you can view the new form through the New Form option on the Compose menu of the Microsoft Exchange Client.