39 Miss. Code. R. 1-6-112
Unless otherwise noted herein, documents which are required to be served on other persons or parties shall be served concurrently with the filing with the Executive Secretary. Service upon a party, service of orders, notices, pleadings, motions and other documents upon a party shall be made by delivering a copy to the party, by transmitting it to the party by electronic means, by facsimile transfer or e-mail, or by mailing to the party or other person at their last known address. Delivery of a copy means handing it to a party, leaving it at the office of a party with a person in charge thereof, or leaving it at the dwelling house or usual place of abode of the party with some person of suitable age and discretion then residing therein. Service by electronic means is complete when the electronic equipment being used by the party being served acknowledges receipt of the material. If the equipment used by the party being served does not automatically acknowledge the transmission, service is not complete until the sending party obtains an acknowledgement from the recipient. Service by mail is complete upon mailing. If a pleading or other document is served by mail, three days shall be added to the prescribed period in which the party being served has to respond or take other action with respect to the pleading. For purposes of service of documents under this section, the term "party" shall also refer to the Commission and the Staff.
Whenever service is made upon a party who is represented by an attorney of record in the proceedings, the service shall be made upon such attorney.
39 Miss. Code. R. 1-6-112