How to set permission on MailItem

Hi ALL,

Requirement : Need to send mail through EWS API with permission level "Do Not Forward".

How can I set the permission like (Do Not Forward) for the mail item?. I didn't find any reference for the same. Please help me on this.

Example code :

ExchangeService service = new ExchangeService(ExchangeVersion.Exchange2010);
EmailMessage email = new EmailMessage(service);
email.Send();

I need to set permission level before sending the mail.

Thanks,

Arun.M

Arunkumar