Kotlin Email Validation (KEV)

There are several ways to achieve this;

1. Using Regex

fun isEmailValid(email: String): Boolean {
  return Pattern.compile(
    "^(([\\w-]+\\.)+[\\w-]+|([a-zA-Z]|[\\w-]{2,}))@"
    + "((([0-1]?[0-9]{1,2}|25[0-5]|2[0-4][0-9])\\.([0-1]?"
    + "[0-9]{1,2}|25[0-5]|2[0-4][0-9])\\."
    + "([0-1]?[0-9]{1,2}|25[0-5]|2[0-4][0-9])\\.([0-1]?"
    + "[0-9]{1,2}|25[0-5]|2[0-4][0-9]))|"
    + "([a-zA-Z]+[\\w-]+\\.)+[a-zA-Z]{2,4})$"
  ).matcher(email).matches()
}

2. Using Android Utils

fun isEmailValid(email: String): Boolean { 
    return android.util.Patterns.EMAIL_ADDRESS.matcher(email).matches()
}

Done.