MFMailComposeViewController submit and cancel buttons not showing

for some reason, the submit and cancel buttons are not displayed, I even inserted the following code at the beginning of the application in appdelegate only when the application starts, but still does not work. Can anyone help thanks

mailController = [[MFMailComposeViewController alloc] init];
        mailController.mailComposeDelegate = self;
        [mailController setToRecipients:[strToEmailAddresses componentsSeparatedByString:@","]];
        [mailController setSubject:@"An Invite from MyGuide"];
        [mailController setMessageBody:@"Join me and your other friends now for free." isHTML:NO];

        if(mailController == nil)
            NSLog(@"Nil");
        else
            [self presentModalViewController:mailController animated:YES];