why is my sending mail not working from MFMailComposeViewController?

I found this source code from here and tried sending mail using it. I successfully got the 'MFMailComposeResultSent' Message, but actual mail is not sent. I don't understand why is not working. Also, I attached an image from NSData, but it doesn't display in mailcomposeview. What is the wrong with this code? Actually, I only need calling native mail app with an attachement image, but I heard there is no way calling the native app with attachement. Please let me know what is wrong with my code. Problem 1: doesn't send a mail from mailcomposeview, Problem 2: doesn't display attached image. Best : running native mail app with attached image. I'll be happily waiting your answers. Thx. ``` -(void) sendMail { NSLog(@"Mail"); MFMailComposeViewController *mfMailView = [[MFMailComposeViewController alloc]init]; NSData *imgData = UIImagePNGRepresentation(imgPreview.image); mfMailView.mailComposeDelegate = self; [mfMailView addAttachmentData:imgData mimeType:@"image/png" fileName:@"Me.png"]; //also tried this //[mfMailView addAttachmentData:imgData mimeType:@"image/png" fileName:@"Me"]; [mfMailView setSubject:@"TE~st"]; [mfMailView setMessageBody:@"Download Me~!" isHTML:YES]; [self presentModalViewController:mfMailView animated:YES]; } -(void) mailComposeController:(MFMailComposeViewController *)controller didFinishWithResult:(MFMailComposeResult)result error:(NSError *)error { switch (result) { case MFMailComposeResultCancelled: NSLog(@"cancel?"); break; case MFMailComposeResultSaved: NSLog(@"saved?"); break; case MFMailComposeResultSent: NSLog(@"Sent succed"); [controller dismissModalViewControllerAnimated:YES]; break; case MFMailComposeResultFailed: NSLog(@"sent failue"); NSLog(@"%@",error); break; default: break; } } ```