begin
  dbms_network_acl_admin.create_acl (
    acl         => 'utl_mail.xml',
    description => 'Allow mail to be sent',
    principal   => 'MICHEL',
    is_grant    => TRUE,
    privilege   => 'connect'
    );
  dbms_network_acl_admin.add_privilege (
    acl       => 'utl_mail.xml',
    principal => 'MICHEL',
    is_grant  => TRUE,
    privilege => 'resolve'
  );
  dbms_network_acl_admin.assign_acl (
    acl  => 'utl_mail.xml',
    host => '<your smtp server host name or address>'
  );
  commit;
end;
/