For Office 365
Step 1: Log in to your Admin Center and click on "Admin".
Step 2: Click "View All" in the left sidebar and select "Services and Add-Ins" under the "Settings".
Step 3: Select the SoSafe Phishing-Reporting add-in.
Step 4: Under "Who has access", click "Edit".
Step 5: Make sure that "Everyone" is selected.
Step 6: If you would like to roll out the addin to specific groups only, verify that you have also assigned the subgroups to the add-in.
For Exchange 2016
Step 1: Log in to your Exchange Admin Center and go to the "Organization" menu. Then open the "Add-Ins" tab.
Step 2: Check the values of the SoSafe Phishing-Reporting Add-In in the "Provided for" column.
Step 3: If you need to edit the distribution groups for the add-in, please check the installation instructions for Exchange 2016.