Line of fax cover propagated when faxing a letter from within the system

Hi, When someone sends a fax from within the patient's chart, it comes via efax (email). The subject line is not clear what the efax is about. Can there be an automatic subject line that states what letter is being sent? For example, when our front desk sends a Client Registration Letter via fax, it would be helpful to have the subject line say Client Registration From. Is that possible?