Filtrar solo los contactos que tienen email

utilizo una clase auxiliar para guardar los datos y poder ordenarlos.
Contacto.h
#import

@interface Contacto : NSObject{
NSNumber *numero;
NSString *email;
NSString *nombre;
}

@property (nonatomic, strong) NSNumber *numero;
@property (nonatomic, strong) NSString *email;
@property (nonatomic, strong) NSString *nombre;

@end

el codigo es:
addressBook = ABAddressBookCreate();

self.people = (__bridge_transfer NSArray *)ABAddressBookCopyArrayOfAllPeople(addressBook);
self.filteredPeople = [NSMutableArray array];

for (id record in people)
{
ABRecordRef person = (__bridge ABRecordRef)record;
NSString *firstName = (__bridge_transfer NSString *)ABRecordCopyValue(person, kABPersonFirstNameProperty);
NSString *lastName = (__bridge_transfer NSString *)ABRecordCopyValue(person, kABPersonLastNameProperty);

NSString *email;
ABMultiValueRef emails = ABRecordCopyValue(person, kABPersonEmailProperty);
if (ABMultiValueGetCount(emails)>0){
email = (__bridge_transfer NSString *)ABMultiValueCopyValueAtIndex(emails, 0);
if (![email isEqualToString:@””]){
// Match by name or organization
ABRecordID abRecordID = ABRecordGetRecordID(person);

// Add the matching abRecordID to filteredPeople
Contacto *c = [[Contacto alloc]init];
c.numero=[NSNumber numberWithInt:abRecordID];
c.email=email;
c.nombre=[NSString stringWithFormat:@”%@ %@”,[firstName capitalizedString],[lastName capitalizedString]];
[filteredPeople addObject:c];
}

}

}
//NSArray *sortedArray;
filteredPeople = [filteredPeople sortedArrayUsingComparator:^NSComparisonResult(id a, id b) {
NSString *first = [(Contacto*)a nombre];
NSString *second = [(Contacto*)b nombre];
return [first compare:second];
}];