Nice idea for the theme. Having a team definitvely fits the theme. Also the game is pretty intuitive and it is clear what to do.
For the gampelay it is not ideal that mails overlap each other. I think an easy solution to get rid of that would be to limit the amount of incoming mails + having fixed spots were they can spawn. In order to keep the randomness you could add an offset to that location. Then you could spawn mails based on the available slots.
Another (maybe more complex) way would be that the player could push around the letters.
The graphics are working and definitvly fine for a jam but of course here is also space to improve. Nice looking graphcis can add a lot to the athmosphere.
Overall a nice game and you did a good job on the music part :-)