Thank you for your enquiry.
It sounds like we could help, but would need to clarify some details to be sure. Formativ only works with the Windows 32-bit client, so if any of your users use WebAccess, the text wouldn’t be added to the subject. Likewise, if any users access your system remotely (i.e. from home computers), they would need to be using the Windows client and have Formativ installed. How sure do you need to be that every message has the given text in the subject?