Sending bulk email with comma separated

That's because you're sending it TO "[email protected]", and BCCing everyone else. If you want it to go TO them, then send it TO them and don't BCC them. So you'd have to loop through them all and send an individual email. You'll be sending a lot more mail, but it will do what you want. This is just standard email stuff and doesn't really have to do with the CI email library. The same would happen if you did the same thing in your regular email client.