SoftBank Intl SMS?

I have a friend in Cambodia who I'm trying to send SMS messages to, however unsuccessfully. I was wondering if this is due to Softbank only sending sms to other softbank users, if I have to get another service plan, or if I just am not putting in the right numbers. Anyone got experience/knowledge about this?

If you mean phone number to phone number message when you say SMS, from a Japanese Softbank phone to a Cambodian carrier phone (not Softbank), then, correct, you cannot do that. You need to get that phone's e-mail address (with @ in it) and send from your Softbank e-mail address.

I believe that it's only between (1) two Sofbank phones or (2) one Softbank and an AU phone that you can simply do number-to-number messages.

I'm not sure about Colombia, but you can text message between Japan and the U.S.(I'm using Softbank, and my friend in the U.S.A. is using something like t-mobile). So, why not go to the website of Softbank and find out?

*Sorry for my English!

sorry!
you're from Cambodia, not Colombia!