Sun Cellular is the newest GSM mobile phone network in the Philippines. It boasts of affordable rates and the newest network in the islands.
Out of over 572 mobile phone networks overseas only about 110 networks will allow Sun subscribers to send and receive text messages. What I mean about receive messages here is that the overseas mobile phone user can initiate a text message even without replying to a Sun subscribers message.
What I am not happy about the 110 networks is that these are scattered over countries and territories that are probably fewer than a thousand Filipinos. These networks include some in Ukraine, a network in Romania, Aruba, Bermuda, Botswana, Cayman Islands and Congo, just to name a few. In Australia, out of the six networks only one is capable of full send and receive.
There are about 400 networks which Sun subscribers can text but the receipients overseas need to save or reply to the Sun SMS message in order so send a message back to Sun Cellular. This is a hastle because the overseas user cannot initiate a text message. Maria in Acapulco cannot send a text message greeting happy birthday to her favourite niece in Cebu while on her coffee break. New Zealand networks and most of the networks in popular countries like the United States, Canada, Britain and so on are under this category.
Last and the least are the 62 networks which Sun subcribers can only send a message and can never receive a reply. Networks like Vodafone in the UK, Etisalat in the UAE and Telenor in Norway to name a few.
Still the best networks for international text messaging in the Philippines are Globe Telecom and Smart Communications. Sun Cellular has a long way to go.
Source
Sun Cellular: International Text Messaging