I upgraded my iPhone 4 to iO 5 last night, setup iCloud and went to sleep.
In the morning, I noticed that my fully charged phone had completely discharged and my Mac iTunes was showing a notice that sync had failed with the iPhone.
Later today, I got an email from AT&T saying that I have used my 200 MB plan by 90% and I should take care.(It was about 100MB yesterday)
Did the iCloud sync over 3G last night? (My iPhone and Mac were both on my home wifi network that did not break during the night)
I was playing with the iMessage feature and I sent an email to one of my other (non-AppleID) email IDs from it, just to check. The email came thru with the email ID being firstname.lastname@example.org and this was when I got that 90% email from AT&T.
I don't use SMS so I've completely disabled it by calling the AT&T call center.
What caused my 3G plan to be over used? The MMS or iCloud?