If you would like to reach out to In-Progress applicants, they must be in PORTAL as Inquiry records first. What you should do is retrieve in PWS to have the most up to date records, find In Progress Applications, run through and process each in the list (if you have not processed them yet indicated by the linking column or if there is New Data otherwise no need to process again). Once all records in the find are marked as linked to PORTAL with no new data, click one of the green arrows and that will land you in the same found set in PORTAL. Now you can Broadcast this found set in PORTAL!
Please keep in mind that some applicants may not have provided a contact email as of yet if they are In Progress and only filled out the first page of the application so far. In this scenario, you could constrain your found set in PORTAL to omit those that have a Pa_email in PORTAL to see who has not provided Pa_email in PWS yet and then you can manually (on a one off basis) click the Account green arrow in PWS to access the account holder’s email so that you can email those applicants individually.