Finally this is it; you can now manage your Yammer domains from the Office 365.
This means if you already have additional domains associated with Office 365, they will be automatically added into your Yammer network.
If you are adding or removing domains from Office 365, this will be automatically added/removed from Yammer.
No more administration tasks to associate additional domains with your Yammer network.
If you want to check if this feature is already activated for your Office 365 tenant/Yammer network, logon to Yammer with your admin credentials and access to the Network Admin settings of your Yammer network
Then go to the Network Migration and check the list of domains associated with your network (you should see your primary domain used when creating your Yammer network, and the additional ones below)
Then you can migrate/consolidate the previous Yammer networks created for these associated domains
