Alguna forma de veriificar si el Correo es gmail o hotmail especificamente? al registrar un usuario?

Verna quiero saber si una pagina php puede permitir que solo correos gmail, hotmail, yahoo sean los disponibles para registrarse estuve leyendo pero no se como configurar esto de forma que al final haga die si el correo no es ninguno de los anteriormente nombrados.

<?? <?php   function validar_email($  email){      $  exp = "^[a-z\'0-9]+([._-][a-z\'0-9]+)*@([a-z0-9]+([._-][a-z0-9]+))+$  ";      if(eregi($  exp,$  email)){      if(checkdnsrr(array_pop(explode("@",$  email)),"MX")){        return true;     }else{        return false;     }      }else{         return false;      }  }   // para aplicarla   if (validar_email($  _GET[correo])){  // coloco las instrucciones  echo 'Es correcto el correo';  }else{  echo 'Es falso el correo';  }   ?> 

How to sync hotmail contacts in both directions?

with iPhone, you just add your Hotmail account and it syncs your contacts both ways seamlessly.

I have to use Hotmail, not gmail, as I primarily use outlook on a PC, and gmail provides no (free) outlook sync method for contacts and calendar.

Now I have android phone, I cant find any way to do this. I have tried the following:

1) add Hotmail as an exchange account.

This puts your Hotmail contacts into the android phone app. This is HALF the job. However, if you edit a contact, it does not sync back to Hotmail. The edit is local to the phone. If you lose your phone, you lose the number.

Note: to get this to work, you have to create a manual setup, chose exchange, then set the server to

So I removed the account and went back to zero contacts in the android phone app.

2) install outlook app and add hotmail account.

Next I installed outlook app and added my Hotmail account. Your contacts are visible in the people tab of outlook BUT YOU CANT EDIT THEM OR ADD NEW ONES. It also adds an android account called “outlook”, and puts your Hotmail contacts in the android phone app. Great no? NO. Again, if you edit a contact, it stays on the phone, the sync is one way. Even worse, if you add a new contact as a Hotmail contact, it does not sync anywhere.

Am I missing something, or is outlook/Hotmail on android completely broken/ only half implemented?

Surely there is someone who uses outlook on a PC and has an android phone, and needs to sync contacts two ways, something I have been doing with out issue for the last 10 years with windows CE phones and iphones?

Google nexus 6 + Android 6

=== update ===

Recently, MS “upgraded” hotmail to use exchange protocols for synchronization, rather than the hotmail connector, so I decided to dust off the nexus and try again.

  1. start off with no contacts in the phone app, outlook for android installed with no accounts.
  2. Add email as an exchange account in outlook for android.
  3. Wait
  4. Now I see

a) all my contacts in outlook for android, but they are not editable, they are read only. If I change a contact in outlook on my desktop, I see the change in outlook for android. But no way to get changes or new contacts back the other way. Unfortunately, contacts in outlook for android are largely useless as I don’t use email on my phone and would rarely use outlook for android, I only installed it to try to get contacts to sync. I need the contacts in the phone’s phone book.

b) All my contacts appear on the android phone app, but its a one way sync only. If I change a contact on the phone, the change is not reflected or saved anywhere. If I add a new contact, its not synced or saved anywhere. If i updated a contact on the pc or in hotmail web browser, this change is synced back to the phone, overwriting any changes I have made to an existing contact on the phone. Contacts are correctly marked as belonging to the hotmail/exchange account.