Ole Miss football vs. Mountain West
San Jose State Spartans: Distance between these teams probably isn't the only reason these teams haven't met yet. The Spartans just don't have a strong enough Group of Five resume yet for the Rebels to put them on the schedule.
Utah State Aggies: Same as above.
Colorado State Rams: Colorado State has shown flashes of greatness in the past few years. A matchup between the Rebels and Rams would be very interesting to see, so hopefully they meet soon, but it would probably be a postseason game.
Hawai'i Rainbows Warriors: Distance is most likely the biggest factor for there being no matchups between these teams.
New Mexico Lobos: Same as above.
San Diego State Aztecs: A postseason matchup would be the most likely instance these two teams meet. It would be fun to see these two battle it out for a spot in the next round of the College Football Playoff.
Nevada Wolf Pack: It is reasonable to say that Nevada and Ole Miss won't meet anytime soon even in postseason play. The Wolf Pack would need to strengthen their resume substantially.