hi there! I just recently bought my first smartphone and have a question: There is always this symbol on my sent messages (sms) that looks like the symbol that says "problem with the delivery" (it's a little envelope with a green exclamation mark). but my friends always get my messages. does anyone know what this symbol means? I also have the problem that I don't get a delivery status notification even though I clicked "yes" for "always send a notification"... can anyone help? thanks!!