input: from typing import List
  
  def send_automated_emails(recipient_emails: List[str], sender_email: str, password: str) -> None:
      """
      Send an automated email to a list of recipient emails.
      >>> send_automated_emails(["email1@example.com", "email2@example.com"], "example@gmail.com", "example_password")
      Email sent successfully.
      Email sent successfully.
      """
      for email in recipient_emails:
          with smtplib.SMTP('smtp.gmail.com', 587) as server:
              server.ehlo()
              server.starttls()
              server.login(sender_email, password)
  
              subject = 'Automated Email from Program'
              message = 'Message body'
  
              server.sendmail(sender_email, email, 'Subject: ' + subject + '\n\n' + message)
              print('Email sent successfully.')
output:     
  import smtplib
  