If I use the email address "appname.app@company.co.za" then it doesn't work but if I try appname@company.co.za then it works.
I've tried this from How to open mail app from Swift
let url = NSURL(string: "appname.app@company.co.za")
UIApplication.sharedApplication().openURL(url!)
and this
let url = NSURL(string: "appname.app@company.co.za".stringByAddingPercentEscapesUsingEncoding(NSUTF8StringEncoding)!)
UIApplication.sharedApplication().openURL(url!)