Written policy and procedure shall specify that indigent inmates shall be permitted:

1. (1) An unlimited number of postage-free letters each week for privileged confidential correspondence, excluding attorneys;
2. (2) Three postage-free letters each week for general correspondence; and
3. (3) Sheriffs or designees may develop procedures to allow indigent inmates to mail postage-free letters each week to their attorneys of record on any pending criminal matter.