It's based on Google Translate service, and You need internet connection for access. Try to avoid AUTO_DETECT option for your writing language. I suggest to put exactly the 'name' of your language in list "From:". Depends on your phone, which language letters and characters are supported. You can always, do 'undo' and correct your sentences in message. Delivery report is enabled.
In Lite version, option to pick up contact from Contacts or address book, from your phone or SIM card, is disabled. That function is only enabled in DONATE version.