#!/usr/bin/env python
# -*- coding: utf-8 -*-
import re

archivo = open("mail.txt", "r")
resultado = open("destino.txt","a")
emails = list(set([linea.strip() for linea in archivo]))

body_regex = re.compile('''
    ^(?!\.)                            # name may not begin with a dot
    (
      [-a-z0-9!\#$%&'*+/=?^_`{|}~]     # all legal characters except dot
      |
      (?<!\.)\.                        # single dots only
    )+
    (?<!\.)$                            # name may not end with a dot
''', re.VERBOSE | re.IGNORECASE)
domain_regex = re.compile('''
    (
      localhost
      |
      (
        [a-z0-9]
            # [sub]domain begins with alphanumeric
        (
          [-\w]*                         # alphanumeric, underscore, dot, hyphen
          [a-z0-9]                       # ending alphanumeric
        )?
      \.                               # ending dot
      )+
      [a-z]{2,}                        # TLD alpha-only
   )$
''', re.VERBOSE | re.IGNORECASE)

def is_valid_email(email):
    if not isinstance(email, str) or not email or '@' not in email:
        return False
    
    body, domain = email.rsplit('@', 1)

    match_body = body_regex.match(body)
    match_domain = domain_regex.match(domain)

    if not match_domain:
        # check for Internationalized Domain Names
        # see https://docs.python.org/2/library/codecs.html#module-encodings.idna
        try:
            domain_encoded = domain.encode('idna').decode('ascii')
        except UnicodeError:
            return False
        match_domain = domain_regex.match(domain_encoded)

    return (match_body is not None) and (match_domain is not None)

for email in emails:
  emails = list()
  if is_valid_email(email)  and not email in emails:
    emails.append(email)
    resultado.write(email + '\n')

resultado.close()
archivo.close()