iMessage sent as sms/mms text
Something to watch out, well for me since @o2 changed their policy on sending MMS is that an iMessage can go as a SMS/MMS message out of your allowance if it is unavailable. This only applies to the iPhone (actually I don't know about iPad with 3G) but you can turn this feature on or off in within Settings > Messages > Send As SMS (see image below).
Apple support doc: http://support.apple.com/kb/HT3529
Comments
Thanks a lot for this. I keep getting caught out texting my cousin in NYC. Button is blue initially but by the time O2 think about it, it sends it as SMS long after I've gone on to do something else. Crafty!!!
