Is it possible to Prevent TO fileld to be edit in MFMailComposeViewController

in my Application i am using MFMailComposeViewController for emails... I am Adding to Field in it programmaticly... I want To prevent user to edit the TO field,

User can't change TO field's email address... I am not able to find neither i know if it is possible or not

It is not necessary but still code is

NSArray *arr = [NSArray arrayWithObject:Emailstr];
   开发者_如何学运维 MFMailComposeViewController* controller = [[MFMailComposeViewController alloc] init];
    controller.mailComposeDelegate = self;
    [controller setToRecipients:arr];
    [controller 
    [controller setMessageBody:@"Hello there." isHTML:NO]; 
    [self presentModalViewController:controller animated:YES]; 

It's not possible.