A party shall serve pleadings and papers filed after notice issued pursuant to Regulation .06 of this chapter: Upon each party's attorney; or Upon the party if a party is not represented by counsel. A party shall make service by: Delivery of a copy; Mailing it to: The address most recently stated in a pleading or paper filed by the attorney or party; or To the last known address, if no address is stated on the most recent pleading or paper filed by the attorney or party; or Any other method agreed upon by the parties. A party shall include in its pleadings a certificate of service showing the date and manner of making service.