Even if you pay for it and don't use g, you can't know with absolute certainty that your email is going to get to the person you are sending it to. There's a h

Even if you pay for it and don't use g, you can't know with absolute certainty that your email is going to get to the person you are sending it to. There's a high 9's probability that it will arrive safely, but there's several ways that things can go wrong, simplest of which is that you are deleted by a misconfigured filter. There are US ISPs (cough sbcglobal) that routinely throw away mail from some arbitrary IPs despite there being absolutely no SPAM blacklist entries for the IP, even if you are replying to a mail sent from one of their clients. outlook.com once, (and maybe still does) blocked email from an entire C-block for some reason. (edit - grammar)