Hi @it33, thanks for your quick response. Yes, that's the troubleshooting docs that I have looked. I have also tried running the query in my AD and its returns over 500 items. I was using a more complex filter but for debugging purposes I've reduce it to the one I submitted here. I'm quite sure the filter works because I've use it in other applications like Confluence and Zimbra.
Question, should the user login as domain\username or just username? As shown in the logs, I've tried either way and it didn't work. Are the accounts created the first time a new user logs in or during the sync? If its during the sync, can I query the DB how many accounts Mattermost found? Sorry, I'm not familiar with postgres and the Mattermost schema so didn't dig further.
Thanks!