Last weekend, I did apply an update to the Exchange 2016 server. Since then, it appear that the "AUTH LOGIN" dosent work anymore on CRD.
I'm not sure if I need to change something on the CRD side or on the Exchange side, but some of my Distribution Group are giving error now "550 5.7.133 RESOLVER.RST.SenderNotAuthenticatedForGroup; authentication required; Delivery restriction check failed because the sender was not authenticated when sending to this group".
I can see the user is authenticated, since he's using "Client Proxy" when using authentifications and "Default Proxy" when not autenticated.
Any idea where I should look ?
And no, I can't disable the authentication for those group, I want to restrict who can send email to this group! :)