If the button is grayed out when trying to report a mail and/or an e-mail mail cannot be reported, this might be caused by two things.
Cause 1: The button cannot conect to the SoSafe server to check the license and is therefore not activated correctly. You must ensure that the following URLs can be accessed:
Cause 2: You are trying to report an SMTP Non-Delivery Notification ("Bounce Message"). Such messages do not have their own "real" sender (envelope sender) but are notifications from the mail server.
From a technical point of view, such messages are not real e-mails and therefore cannot be reported using the report button. If a user has a very high number of such notifications in his inbox, you should check whether the user has actually sent a lot of mails, e.g. to unknown addresses, or whether the user's inbox or account has been taken over and is being misused for the mass sending of spam or phishing mails.