GNU Mailutils

sql {
  # Set SQL interface to use.
  interface ‘mysql|odbc|postgres’;
  # SQL server host name.
  host arg;
  # SQL user name.
  user arg;
  # Password for the SQL user.
  passwd arg;
  # SQL server port.
  port arg;
  # Database name.
  db arg;
  # Type of password returned by getpass query.
  password-type ‘plain | hash | scrambled’;
  # Set a field-map for parsing SQL replies.
  field-map map;
  # SQL query returning the user's password.
  getpass query;
  # SQL query to use for getpwnam requests.
  getpwnam query;
  # SQL query to use for getpwuid requests.
  getpwuid query;
}