When sending message to an offline contact, it's not sent ever.
Issue generated from Tuleap's migration script. Originally submitted by: ring user (username)
I turned off my PC with GNOME client, I sent to it a message from Android client, went to home screen and locked the phone, started the PC and GNOME client, message didn't arrive, unlocked screen, message didn't arrive, opened Ring, message didn't arrive. I sent a new message, it arrived.