使用内置的 URL 方案打开 Mail 应用程序

迅速：

if let url = URL(string: "mailto://azimov@demo.com") {
    if UIApplication.shared.canOpenURL(url) {
        UIApplication.shared.openURL(url)
    } else {
        print("Cannot open URL")
    }
}

Objective-C

NSURL *url = [NSURL URLWithString:@"mailto://azimov@demo.com"];
if ([[UIApplication sharedApplication] canOpenURL:url]) {
    [[UIApplication sharedApplication] openURL:url];
} else {
    NSLog(@"Cannot open URL");
}