Moogle messaging "Green arrow"

[ZexionVI6]

I sent a friend a message, but I'm not sure it sent because you can't check sent messages, and I really don't want to overload his mail box if they are going through. I see I've sent him two messages, but one has a green arrow on it. What does that mean?

[Kurando]

You can check any messages you have sent in the Sent tab, but the only thing that can really prevent a message from being received is if the intended player has a full message box. Only 20 pieces of mail can be held at one time, so they often need to be deleted if something is expected (i.e. like mog station items). Green arrow should mean that it's been sent successfully but I would have to check myself to confirm it as not 100% sure