If you start a conversation with somebody using iMessage and the massages are being sent as blue imessages and that person moves to an an area where they don't have a data connection any further messages sent do not arrive until the user is once again on a 3G or wifi data connection etc. They do not auto send as text messages. I work abroad several times a month and always have data roaming off. I talk to several of my contacts by blue iMessage and when I'm aboard, I do not get any of the messages they send me until I am on a data connection. They do not come though as text messages. A second question, after sending a message to somebody using blue iMessage, how can you then force it to send as a text message? I ask this because a colleague of mine has just gone to India and I know he is not on a data connection. Each message I send him stills sends as a blue iMessage and not green text message. I have spoken to him and not of my messages arrive. When he moves to a data connection they all start to arrive. Since we have many imessage conversations going at once, how are we to know if the user has moved out of data range and are not getting my messages? I though the whole point of iMessage warns if a data connection was not available it would send as text?