Miss. Code Ann. § 23-15-681

Except as otherwise provided in this subarticle, all official absentee ballots shall be sent out and returned in envelopes on which there is printed across the face two (2) parallel horizontal bars, each one-fourth (1/4) of an inch wide, extending from one side of the envelope to the other side, with an intervening space of one-fourth (1/4) of an inch, the top bar to be one and one-fourth (1-1/4) inches from the top of the envelope, and with the words “OFFICIAL ELECTION BALLOTING MATERIAL-VIA AIR MAIL” between the bars. In the upper right corner of each such envelope there shall be printed in a box the words “FREE OF U.S. POSTAGE, INCLUDING AIR MAIL.” All printing on the face of such envelopes shall be in black, and there shall be printed in black in the upper left corner of all such ballot envelopes an appropriate inscription for the return address of the sender.