Can we write javascript to run in the webmail? If so how do we handle such situation

Could any one of you explain 开发者_开发技巧me for the below situation. When I open a new mail the content of the mail(mini application with four or five modules) should be displayed in javascipt? How do u do that?

Put it on a website and send people the link. I don't know of any mail application which is silly enough to allow javascript to run.