I need to count the number of unique family units from one column and who needs an invitation based on another column

Hello! I have made a wedding tracker in Excel, and I'm using it to track who we have and have not sent save the dates and RSVPs to, but I want to add a formula that will track how many we have to mail out. The relevant information is:

• Family units are being tracked in column E (Page "Prio1", TABLE1[Family Unit])
• Save the Date status is being stored in column J (same page, Table1[StD])
  • Uses a list of "Not Sent", "Labeled", "Sent"

I've got a metrics tracker on another page where I am using the formula to track total family units:

=SUMPRODUCT(1/COUNTIF(Table1[Family Unit],Table1[Family Unit]))

Any advice on how I can track how many family units we have to mail out?