You can choose not to display the following items on the mail form when you are creating a message. If you choose not to display an option, the option is hidden until you choose to display it again.
Bcc -- removes the bcc recipient field
Additional Mail Options -- removes the High priority, Return receipt, Sign, and Encrypt checkboxes from the mail form. These options are still available to you using the Delivery Options menu.
Sender Information -- Removes the informational text that shows the sender, date, and time stamp for the message.