title: Why does SendGrid allow me to send emails from any address?
body: <p>I have a local python file that I'm using to send emails through sendgrid's SMTP:</p>
  
  <pre><code>gmail_sender = "example@gmail.com"
  server_username = "apikey"
  server_password = prod.CONFIG['sendgrid_SMTP']
  
  server = smtplib.SMTP_SSL('smtp.sendgrid.net', 465)
  server.login(server_username, server_password)
  
  email_information['From'] = gmail_sender
  
  server.sendmail(email_information['From'], email_information['To'], 
      email_information.as_string())
  </code></pre>
  
  <p>I'm confused about who is sending the email. I replaced gmail_sender with multiple different emails, and without having to give the password to those emails, I could send an email through sendgrid's SMTP. In the from section of the email I sent, it says the email I put as the gmail_sender plus "via sendgrid.net." I can make it seem like anyone sent the email, isn't this a security concern?</p>
  
  <p>Any guidance is appreciated :)</p>