During his junior season, he received unanimous All-American honors and won the Ray Guy Award.
As a sophomore, he did not punt at all and made only one kicking attempt, which came when he missed a 43-yard field goal try in the season-opening 44–45 loss to UCLA.
During the Alabama game, he broke the NCAA football bowl subdivision single-game record with a 60.8 punting average.
During the November 2018 game against University of Alabama at Birmingham, he made his 14th punt of 60 or more yards breaking the NCAA FBS single-season record set in 2005 by former Wake Forest punter Ryan Plackemeier.
[20] Following the regular season, Mann received first-team all-SEC honors from the league's coaches[21] and the Associated Press[22] and was also named the SEC Special Teams Player of the Year.
[35] Since he earned All-America honors from all five NCAA-recognized selectors (AP, AFCA, FWAA, Sporting News, and WCFF), he became the 10th unanimous All-American from Texas A&M.
[40] During the game against the Los Angeles Rams, Mann made a game-saving, open-field tackle on punt returner Nsimba Webster that helped seal the Jets' 23–20 victory.
He also had a 17-yard completion and had a successful onside kick in a 31–30 win over the Cleveland Browns, earning AFC Special Teams Player of the Week.
[50] On December 11, 2023, Mann faked a punt and threw a 28-yard completion to WR Olamide Zaccheaus in a 13–33 loss to the Dallas Cowboys.