* * IMPORTANT – DO NOT USE THE SIMULATOR FOR THIS. * *

Even in 2016, the simulators very simply do not support sending mail from apps.

Indeed, the simulators simply do not have mail clients.

But! Do see the message at the bottom!

---

Henri has given the total answer. You MUST

— allocate and initiate MFMailComposeViewController in an earlier stage, and

— hold it in one static variable, and then,

— whenever it’s needed, get the static MFMailComposeViewController instance and use that.

AND you will almost certainly have to cycle the global MFMailComposeViewController after each use. It is not reliable to re-use the same one.

Have a global routine which releases and then re-initializes the singleton MFMailComposeViewController. Call to that global routine, each time, after you are finished with the mail composer.

Do it in any singleton. Don’t forget that your app delegate is, of course, a singleton, so do it there…

@property (nonatomic, strong) MFMailComposeViewController *globalMailComposer;

-(BOOL)application:(UIApplication *)application
   didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
    {
    ........
    // part 3, our own setup
    [self cycleTheGlobalMailComposer];
    // needed due to the worst programming in the history of Apple
    .........
    }

and…

-(void)cycleTheGlobalMailComposer
    {
    // cycling GlobalMailComposer due to idiotic iOS issue
    self.globalMailComposer = nil;
    self.globalMailComposer = [[MFMailComposeViewController alloc] init];
    }

Then to use the mail, something like this …

-(void)helpEmail
    {
    // APP.globalMailComposer IS READY TO USE from app launch.
    // recycle it AFTER OUR USE.
    
    if ( [MFMailComposeViewController canSendMail] )
        {
        [APP.globalMailComposer setToRecipients:
              [NSArray arrayWithObjects: emailAddressNSString, nil] ];
        [APP.globalMailComposer setSubject:subject];
        [APP.globalMailComposer setMessageBody:msg isHTML:NO];
        APP.globalMailComposer.mailComposeDelegate = self;
        [self presentViewController:APP.globalMailComposer
             animated:YES completion:nil];
        }
    else
        {
        [UIAlertView ok:@"Unable to mail. No email on this device?"];
        [APP cycleTheGlobalMailComposer];
        }
    }

-(void)mailComposeController:(MFMailComposeViewController *)controller
     didFinishWithResult:(MFMailComposeResult)result
     error:(NSError *)error
    {
    [controller dismissViewControllerAnimated:YES completion:^
        { [APP cycleTheGlobalMailComposer]; }
        ];
    }

{nb, fixed typo per Michael Salamone below.}

Have the following macro in your Prefix file for convenience

#define APP ((AppDelegate *)[[UIApplication sharedApplication] delegate])

Also here’s a “minor” problem which can cost you days: https://stackoverflow.com/a/17120065/294884

---

Just for 2016 FTR here’s the basic swift code to send an email IN APP,

class YourClass:UIViewController, MFMailComposeViewControllerDelegate
 {
    func clickedMetrieArrow()
        {
        print("click arrow!  v1")
        let e = MFMailComposeViewController()
        e.mailComposeDelegate = self
        e.setToRecipients( ["[email protected]"] )
        e.setSubject("Blah subject")
        e.setMessageBody("Blah text", isHTML: false)
        presentViewController(e, animated: true, completion: nil)
        }
    
    func mailComposeController(controller: MFMailComposeViewController, didFinishWithResult result: MFMailComposeResult, error: NSError?)
        {
        dismissViewControllerAnimated(true, completion: nil)
        }

---

However! Note!

These days it is crappy to send an email “in app”.

It’s much better today to simply cut away to the email client.

Add to plist …

<key>LSApplicationQueriesSchemes</key>
 <array>
    <string>instagram</string>
 </array>

and then code like

func pointlessMarketingEmailForClient()
    {
    let subject = "Some subject"
    let body = "Plenty of <i>email</i> body."
    
    let coded = "mailto:[email protected]?subject=\(subject)&body=\(body)".stringByAddingPercentEncodingWithAllowedCharacters(.URLQueryAllowedCharacterSet())
    
    if let emailURL:NSURL = NSURL(string: coded!)
        {
        if UIApplication.sharedApplication().canOpenURL(emailURL)
            {
            UIApplication.sharedApplication().openURL(emailURL)
            }
        else
            {
            print("fail A")
            }
        }
    else
        {
        print("fail B")
        }
    }

These days, that is much better than trying to email from “inside” the app.

Remember again the iOS simulators simply do not have email clients (nor can you send email using the composer within an app). You must test on a device.