Mississippi Code Title 23. Elections § 23-15-789

The electors chosen shall meet at the seat of government of the state on the first Monday after the second Wednesday in December next following their election, and shall there give their votes for President and Vice-President of the United States, and shall make return thereof agreeably to the laws of the United States; and should any elector so chosen fail to attend and give his vote, the other electors attending shall appoint some person or persons to fill the vacancy or vacancies, who shall attend and vote as electors; and such appointment shall be forthwith reported to the Secretary of State.