by Mathew Gancarz.
Hi Joost, we use external DB auth (though currently on 2.5.x) and I don't think our implementation sends an automated welcome message. I dug around briefly the demo.moodle.net config also and could not find any option for a welcome message.
Is the sync that you are doing, via the /enrol/database/cli/sync.php script? I typically run it with the --verbose switch to monitor the actions being taken.
Do you have a sample of the message that gets sent?