input: Write a python function to send an email using smtplib.
  assert send_email("sender_email_id", "sender_email_id_password", "receiver_email_id", "Message_you_need_to_send")=="Email sent successfully to recipient"
output: def send_email(sender_email, sender_password, receiver_email, message):
      import smtplib
      from email.mime.text import MIMEText
  
      msg = MIMEText(message)
      msg['Subject'] = 'Subject'
      msg['From'] = sender_email
      msg['To'] = receiver_email
  
      try:
          with smtplib.SMTP_SSL('smtp.gmail.com', 465) as server:
              server.login(sender_email, sender_password)
              server.sendmail(sender_email, receiver_email, msg.as_string())
          return "Email sent successfully to recipient"
      except Exception as e:
          return str(e)