I’ve recently started using Office 365 Groups for various client and project activities, but have been personally limited with the lack of visibility within my Outlook client.
Office 365 Unified Groups are supposed to be available within OOTW and Outlook 2016, however I couldn’t access from within the thick client
After doing some testing, it appeared to be specific to a single tenancy – Groups would appear in Outlook for another tenancy. Doing some digging, there appears to be two main requirements for Groups to appear in Outlook 2016: Outlook has to be running in cached mode and Autodiscover must be working.
Now when I say Autodiscover must be working, the Autodiscover record for the domain must be pointing at Exchange Online.
By default, when you create an Office 365 tenancy, you are assigned a tenancy address similar to domain.onmicrosoft.com. This remains your default domain unless you change it to a company vanity domain.
In my specific case, the default tenancy domain had been changed to a vanity domain – which normally wouldn’t cause an issue. When a Group is created it uses the default domain to create the email address, so if the domain name is the tenancy address you would end up with a Group email address of unifiedGroup@domain.onmicrosoft.com.
In this scenario you should never have any issues with Groups – even in a hybrid environment, the Autodiscover record for domain.onmicrosoft.com will point at Exchange Online.
In my specific case, the Groups had been created with unifiedGroup@customdomain.com. The custom domain wasn’t the primary email domain, it was an additional domain that didn’t have any Autodiscover records associated with it, hence no Groups appearing in Outlook!
A quick hostfile change later to test this (selecting one of the IP addresses that resolved to Autodiscover.outlook.com) resulted in all of my Groups appearing in Outlook
An alternate fix was to use the set-UnifiedGroup <name> -emailaddress SMTP:unifiedGroup@domain.onmicrosoft.com, smtp:unifiedGroup@customdomain.com to change the primary SMTP address back to the onmicrosoft.com tenancy address
Or alternatively, make sure your default domain has the correct Autodiscover DNS records