I have a user on O365 whos emails are not working on his Outlook 2016 and strangely hi s iphone is also not recieving emails anymore since this morning.
I reset and unlock his password from AD and synced to O365 but still same issue on both iphone emails and Outlook client.
OWA is working !! and he is able to send recieve emails there.
Where do I start troubleshooting from ?