Beneficial long communication in the multiplayer electronic mail game

In the two-player electronic mail game (EMG), as is well-known, the probability of collective action is lower the more confirmations and reconfirmations are made available to players. In the multiplayer EMG, however, we show players may coordinate on equilibria where they require only few of the available confirmations from each other to act. In this case, increasing the number of available confirmations may either create equilibria with positive probability of collective action when none existed before, or may increase the probability of collective action, if equilibria with positive probability of collective action already existed for fewer available confirmations.