If you are texting to Verizon #'s, you can tell if the message was actually received on the phone. The Sent message (in your Sent messages folder) will have a green check mark. If you are sending to another carrier, you will not get a green check, just the green arrow that signifies successfully SENT.
thanks...and i don't mean to get too weird about this...but just because i can see it was sent, doesn't mean it was actually delivered to their phone; right? That's correct - since they are on other carriers, it will always show as SENT, never DELIVERED. The only messages that will show as DELIVERED are those sent to other Verizon cell phones. And you still don't know if they read the message or not, it just means they received it on their phone. or does it? one number is a sprint, one is at&t