Sometimes, when there's no wifi or mobile data is switched off, people I regularly send to/receive messages from end up as SMS/text conversations. These all appear just fine on my iPhone, but unless it's actually on the same wifi network AND they're switched on AND not sleeping, my Macs do not pickup the historic SMS/texts when they wake up whereas they will "see" the historic iMessages and "catch-up" iMessage conversations. When they are awake and on the same WiFi text message forwarding behaves as expected, i.e. I can send and receive texts on the Yosemite Messages app. Is this expected behaviour or am I doing something wrong?