MailItem.Permission Property (Outlook)
Sets or returns an OlPermission constant that determines what permissions to grant to the recipients of the e-mail item. Read/write.
The Permission property should be synchronized with the PermissionTemplateGuid property to accurately reflect the permission status of the MailItem. Setting the PermissionTemplateGuid property to a valid GUID also sets the Permission property to OlPermission.olPermissionTemplate.
When no Information Rights Management (IRM) has been set up, (in which case the Permission property is OlPermission.olUnrestricted), or the restriction is not to forward the MailItem, (in which case the Permission property is OlPermission.olDoNotForward), the value of the PermissionTemplateGuid property should be an empty string.
Although you can view content that is protected by IRM on any computer that is running the 2007 Microsoft Office system or a later version, you must have Microsoft Office Professional Edition 2003, Microsoft Office Outlook 2007, or a later version of Outlook to create or send an e-mail that is protected by IRM.
This Microsoft Visual Basic for Applications (VBA) example uses the Send event and sends an item with a 'Do not forward' restriction. You must place the sample code in a class module such as ThisOutlookSession, and the SendMyMail procedure must be called before the event procedure can be called by Microsoft Outlook. Replace 'Dan Wilson' with a valid recipient name before you run this example.