Under Account Settings > Notifications you create alerts by specialty, subspecialty, seniority and region, with other filters available. When a physician matching an alert completes onboarding, you get an email (and SMS if you'd like) and they drop into your Recommended feed. The link in the email takes you straight to their profile.
Your Messly account manager will set these up with you during onboarding, and you can change them at any time. If you have no alerts set, you won't hear about any physicians.