I'm trying to send an iMessage to a friend that's currently traveling overseas. We both have iPhones. When I sent her a message to her number from my iPhone, it sent it as an iMessage (blue). However, about 5 minutes later, it switched to a SMS (green). She's most probably not data roaming, might have taken out her SIM card, and is connecting to Wi-Fi intermittently. I do have the "Send as SMS" option enabled in the Messages settings. Which makes me wonder, will she receive my message? And besides, when iOS sends a message as SMS, does it discards the original iMessage? Thanks!