title: MFMailComposeViewController canSendMail returns YES but not sending mail in iOS
body: <p>The following is my code to send an attachment in a mail. This works fine. I am able to send mails but I don't always receive the mails.</p>
  
  <pre><code>MFMailComposeViewController *picker = [[MFMailComposeViewController alloc] init];
  picker.mailComposeDelegate = self;
  
  // Set the subject of email
  [picker setSubject:@"My data file"];
  
  // Add email addresses
  
  [picker setToRecipients:[NSArray arrayWithObjects:emailId, nil]];
  
  
  // Fill out the email body text
  NSString *emailBody = @"Hello, \n Please find the data from the iOS app in the attachments.\n\n Thank you.\nMy Team.";
  
  // This is not an HTML formatted email
  [picker setMessageBody:emailBody isHTML:NO];
  
  // Create NSData object from file
  NSData *exportFileData = [NSData dataWithContentsOfFile:filePath];
  
  // Attach image data to the email
  [picker addAttachmentData:exportFileData mimeType:@"text/csv" fileName:  [self.CSVNameTextField text]];
  
  
  // Show email view
  
  if ([MFMailComposeViewController canSendMail]) {
  
      [self presentModalViewController:picker animated:YES];
  }
  </code></pre>