https://www.facebook.com/groups/python/permalink/643166999857201/

main.py

################
known_domains = {
  "hotmail.com": [],
  "gmail.com": [],
  "yahoo.com": [],
  "mail.ru": [],
}
notfound = []
################

print("Enter five emails to test!")
for i in range(5):
  data = raw_input("mail: ")
  mail = data.lower()
  domain = data.split("@")[1]
  if domain in known_domains:
    known_domains[domain].append(mail)
    print "Domain '%s'" % domain
  else:
    notfound.append(mail)
    print "Domain not found"
  print ""
    
print "Gmail:", known_domains["gmail.com"]
print "Hotmail:", known_domains["hotmail.com"]
print "Yahoo:", known_domains["yahoo.com"]
print "Mail.ru:", known_domains["mail.ru"]
print "Not found:", notfound