How to validate email id in iPhone SDK?

This is prefect method to validate email address valid or not. In this method I'm using "NSPredicate" and "Name Regex" to validate email-ID

NSString *email = textFieldemail.text;
NSString *emailRegEx =
@"(?:[a-z0-9!#$%\\&'*+/=?\\^_`{|}~-]+(?:\\.[a-z0-9!#$%\\&'*+/=?\\^_`{|}"
@"~-]+)*|\"(?:[\\x01-\\x08\\x0b\\x0c\\x0e-\\x1f\\x21\\x23-\\x5b\\x5d-\\"
@"x7f]|\\\\[\\x01-\\x09\\x0b\\x0c\\x0e-\\x7f])*\")@(?:(?:[a-z0-9](?:[a-"
@"z0-9-]*[a-z0-9])?\\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?|\\[(?:(?:25[0-5"
@"]|2[0-4][0-9]|[01]?[0-9][0-9]?)\\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-"
@"9][0-9]?|[a-z0-9-]*[a-z0-9]:(?:[\\x01-\\x08\\x0b\\x0c\\x0e-\\x1f\\x21"
@"-\\x5a\\x53-\\x7f]|\\\\[\\x01-\\x09\\x0b\\x0c\\x0e-\\x7f])+)\\])";

NSPredicate *regExPredicate =
[NSPredicate predicateWithFormat:@"SELF MATCHES %@", emailRegEx];
BOOL myStringMatchesRegEx = [regExPredicate evaluateWithObject:email];


if(!myStringMatchesRegEx)
{
UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"email" message:@"invalid email-ID, please provide a valid email id." delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
[alert show];
[alert release];
}
else
[self prepareHmlDataAndSendEmail];

This is another one of  a simplest method to validate an email id on a text box in iphone development

if (! (([txtMailId.text rangeOfString:@"@"].location != NSNotFound) && ([txtMailId.text rangeOfString:@"."].location != NSNotFound) && [txtMailId.text rangeOfString:@"@"].location < [txtMailId.text rangeOfString:@"."].location ) )
{
UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"email" message:@"invalid email-ID, please enter a valid email id." delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
[alert show];
[alert release];
}
else
[self prepareHmlDataAndSendEmail];