You have to use the filter-formula, but I do not know how the rest of your setup is made.
It’s much easier for me and others to help you if you share your doc with us. We can take a look into the formulas and everyone can make a copy of the document so we don’t get in the way of each other.
Please follow this guide to share your doc with us:
I want it to act as a template and then each client will have a “copy” on their “profile” where I can then track the progress of each message with a status