I'm implementing MST in a Office-365 Business Premium environment. On Teams admin center I have the following settings: - Org-wide settings > External access : Both Parameters are enabled - Org-wide settings > Guest access > "Allow guest access in Teams" is enabled (actually all parameters are On) - Org-wide settings > Teams upgrade > "Coexistence mode" is "Teams only", and cannot be changed as it is locked by Microsoft I enabled both "External access" and "Guest access" more than two days ago, but when from MST Windows client I initiate a video call and type the email address of a regular/consumer Skype user, it cannot find the user, saying "We didn't find any matches" with no option to look-up further. It seems that it only searches within the tenant, and cannot search for external Skype users. Before MST, the external access was enabled in Skype for Business, and we could call regular/consumer Skype accounts with no problem, but now with Teams we cannot do that anymore. Please advise.