to encrypt the form it needs to be submitted via the form action to an 'https' URL where the sever has an SSL certificate installed.
It is also good practice to place the form on the https URL so those filling in the form can see it is secure (you get the padlock in the browser).
of course just because it show the padlock in the browser if you did not submit it to a https URL it would not be secure, so always do both!
email i'm not sure with, but the best place to ask this would be in either the email forum or the forum relative to the server side language you are using, E.G. ASP , PHP , PERL etc..
"In complete darkness we are all the same, only our knowledge and wisdom separates us, don't let your eyes deceive you."
"If a shortcut was meant to be easy, it wouldn't be a shortcut, it would be the way!