Hi All - I know there are a few posts about external network son Yammer but none seem to have the same error messages I am seeing. We work with various clients in the apprenticeship space and have managed to successful set up a few external networks and add users to them but the last one we are unable to do so. We have made sure the company has the Yammer links whitelisted and we have followed the set up the same we have done with the others but we are getting errors when trying to add the users, We have tried to add them from the network admin page, the group page and the all network space and we either get "An email you entered is not allowed. If you are using a personal email address, try a work one" it isn't a gmail or anything like that it is a work address. We get none of your invitations were sent, please verify the email address below and then we get we dont have the permissions to add this email address. I have global admin access so I know this isnt an issue. Anybody got any clues on the issue?