Strange one for you all.
Emails are hosted with Office 365. Domain all verified and DNS records (autodiscover etc) setup and working well.
For the last 3 days at around 9am one specific user stops getting emails on his iPhone. Having removed the account and tried to resetup it says 'unable to verify'...We have tried on 4G/WiFi with and without SSL. We have also tried resetting network connections to no prevail and made sure IOS is up to date....To confirm this is just happening for 1 user!
We have confirmed the correct credentials and are able to work and sign into OWA and emails work on Outlook client on PC with no problem. We are unable to setup the account (with same error message) on other iphone devices also.
Later in evening (after 8.30pm) we are able to successfully add the account back onto the iphone to find the following day...