UIActivityControllerExample.m

NSURL *pathToPdfFile;

UIActivityViewController *activityController = [[UIActivityViewController alloc] initWithActivityItems:@[ result ] applicationActivities:nil];

NSMutableArray *excludedActivities = [NSMutableArray array];

NSNumber *emailOutEnabled = [self.userPreferences.featureFlags valueForKeyPath:@"research.share.email"];
if (!emailOutEnabled.boolValue) {
    [excludedActivities addObject:UIActivityTypeMail];
}

activityController.excludedActivityTypes = excludedActivities;

[exportController presentViewController:activityController animated:YES completion:nil];