iMessage not delivering on friends traveling

[Donut]

I have been using iMessage for some time, and i notice questionable behaviors that i don't understand




I am in the US with ATT, and sending iMessage to a friend on ATT traveling outside the US.


The iMessage will never be delivered on somebody previously using iMassages and now Traveling and forced to use SMS in rooming.


Why is iMessages not sending them to SMS nuraber ?




So i turned off iMessage to use SMS, and it all worked fine!




Another problem came up!


After using the iPad on IOS 5 i was getting the iMessage on the iPad too, but after turning it off on the iPhone i was still getting messages on iMessage only iPad and not on SMS on iPhone..




i think there is much improvement to be made on the Systems of iMessage, or explain the limitations

[Me]

Get yourself what's app and your smart phone owning frienRAB too.
Much better at sending messages and pictures etc, and no charge if on wireless or using your data bundle