iPhone users rarely send e-mail with typos; instead, they send e-mail with (at best) nonsensical words or phrases in place of what they meant, or (at worst) entirely sensical phrases that had nothing to do with what they meant ('how big is that disk you got last night' -> 'how big is that dick you got last night').
As an iPhone owner, I've learned to double-check everything I type.
Did BlackBerry start putting those messages in first, before Apple did the iPhone?