Contacts receive autoresponders automatically when they subscribe via the Opt-In Forms on your Console website or a Console Opt-In Form embedded on your external website. In this scenario, the system will subscribe them to the autoresponder series associated with the Opt-In Form and they will start receiving the messages setup by you in advance (if any such messages exist in the series).
Other situations are (1) when people buy a product from you (they receive the product autoresponder if you have messages scheduled there) and (2) when you include the subscription to the New Client Autoresponder series in the coaching agreement sent to client to be signed electronically.
On your coach end, in CONTACTS TAB > CONTACT NAME > "Profile" tab > "Autoresponders" section, you will see the subscriptions to autoresponders as checked boxes in front of them and also the date when the prospect subscribed.
No other autoresponders are sent automatically to a contact. In the other case scenarios (contacts added manually by the coach, imported or registered by themselves via the Register menu and page), the system will not send them autoresponders automatically. You would need to manually subscribe them to the autoresponders, either (a) individually (by checking the box in front of them in the "Profile" page > "Autoresponders" section and click on the "SAVE" button) or (b) in group by applying the specific action to a selection of contacts via the Search Contacts tool (a video tutorial about applying actions to multiple contacts).