I know you can send an email out of your app by presenting the user with a MFMailComposeViewController, but can you also send an email without the user having to push any send buttons?
The simple answer is "No".
It is against Apple guidelines. You cannot send mail without user interaction (action on send button).
As an alternate option, you can use power of web server/web service. Send information/data to your web service using web service request and can send an email from you web server. (Note: Mail sender id will not be email id of application user.)
You can try this but remember, it's against Apple guidelines and Apple may reject your app.