MailItem.MessageClass Property (Outlook)
Returns or sets a String representing the message class for the Outlook item. Read/write.
Syntax
expression .MessageClass
expression A variable that represents a MailItem object.
Remarks
This property corresponds to the MAPI property PidTagMessageClass. The MessageClass property links the item to the form on which it is based. When an item is selected, Outlook uses the message class to locate the form and expose its properties, such as Reply commands.