Why aren't my messages being seen on fb to anyone?

[Yaséra]

So I sent a message to someone on Facebook.. (I don't have them as a friend since their settings are weird) and everytime I go back to the messages, they're there.. But still, I was getting no reply.. So I tried sending a message to my other fb account to see what the problem was, and when I logged in on my other account to see my message, I didn't receive anything, which means that no one is.. What's the problem?

[?]

Your privacy settings are to only u