I don't know if this is an error, a license, or a system problem.
I have run into this also. Office365 disabled basic authentication today on our tenant. I am working with them to see what my options are. I used POP3 to pull email from mailbox into WHD. Does anyone have any suggestions? We are not getting our trouble tickets from users.
Your only option is to move to Modern Auth OAUTH2 as MS have advised this will be stopped over 3 ago now.
