Fix an excel/outlook based program

I have a program that reads an .rtf report, converts it to an excel report, mines the appropriate data, mail merges the data into form letters and generates emails to the listed individuals. It can alternatively generate letters and address labels. It was designed for Office 2007, but has stopped working consistently, and is not operable on 2016. There are certain features to this program that detect if a person is "email only" meaning that it will generate an email but no letter, or if there is no email in the appropriate column, it will skip this entry for the email module. The program queues the report for approval before generating the emails and/or letters. It also allows them all to be sent out at once, or one by one. Templates with different letters can be selected.