When I add a client as "Prospect", do they automatically get the "Opt-in" messages?

If you, as coach, are the one who adds the prospect into your system (CONTACTS > +ADD CONTACTS), then the answer is NO, your prospect won't receive autoresponder messages. These messages are received automatically by a prospect when they subscribed themselves using the Opt-In forms on your Coaches Console website. Another situation is when you sent them for signing an agreement that includes the subscription to your New Client Autoresponder series.

The autoresponder messages are not received automatically by a prospect in other circumstances. So, if you added prospects manually and want them to receive an Autoresponder series, you need to subscribe them yourself, as coach, to the autoresponder in CONTACTS > CLIENT NAME > Autoresponder (View All) > check the radio button in the autoresponder series and save.