title: Add an entry depending on existing entry in another table with MYSQL
body: <p>I have two tables (X and Y) with the column E-Mail (column names: EmailX in table x and EMailY in table y). I want to add a column in table X which is filled with "yes" when the Email adress in table X is one of the Email adresses in table Y and "no" when the Email adress in table X is NOT one of the Email adresses in table Y.</p>
  
  <p>How can I do this?</p>
  
  <p>Thanks for your support!</p>