Since the recent Outlook.com update we have received emails saying we need to 'reconnect the account'. Since we have various connected accounts (and a primary alias), autodiscover does not work - and there is no way to manually configure an exchange account in Outlook 2016.
Therefore the only way to 'reconnect' the account is to configure it as EAS which is how it is configured in the first place.....
If I change my primary alias back to my @outlook.com account, and configure Outlook 2016 as such, autodiscover works and the account gets correctly configured as an exchange account. Alas, there is no way to change the properties as such, and am then stuck with sending (from Outlook 2016) with my @outlook.com email address.
Seems I am not the only one, as this thread is more or less the same - with no resolve:
Any suggestions would be much appreciated.