I have no idea, but am curious why.
I would suggest though that you include why, or what other things you need it to do at the same time. I mean like, do you want it to pre-fill the receiver address or something? So like a feedback button?
Does it have to be the actual IOS e-mail program? Did you know that e-mails can be sent without a program or even a sender e-mail account used? For example, think about websites that have you fill out a form to contact them. They send the e-mail via code running off the website. Something like that sounds easier to do in a game than to open an external program.