- (BOOL) isEmail { 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]; return [regExPredicate evaluateWithObject:[self lowercaseString]]; }