I have encountered two different situations.
1. A friend of mine has an itouch in Korea. She iMessaged my e-mail address that I added under my "Receive At" in my settings. We were able to message each other totally fine.
2. A friend of mine in korea also has an iPhone 4. She iMessaged me via the same way as above (my e-mail) and her phone number popped up and we were able to iMessage each other totally fine.
So to answer you question, yes it is possible, just make sure you have your apple id set up in your "Receive At" in your settings.
My question regarding this is how does the texting rate apply? Or does it apply at all? I also noticed that whenever 3g or wifi signal is very weak, it turns an iMessage into an SMS. Will iMessage send international messages via SMS if 3g or wifi signal is weak? or will it wait and send it as iMessage? I am just worried at the end of the month I am going to get a huge bill for texting internationally
Great! Thanks for the insight!
As of your concern: texting rate does not apply to iMessages since it is taken care of through the internet (as long as you do not go over your monthly data allowance in the case you don't have unlimited data). Moreover, if you did not sign up for international SMS with your carrier, then even if you try to purposely text an international number, it will give you an error (I have tried to text my parents abroad at one time and this was the case). Thus, I would say that in the event you are out of 3g or wifi signal, it will either wait to send the iMessage or will just give you an error instead. In any event, you should be fine!