Cosmail can be played by 3 to 6 players and 1 game master. Each player has two planes and one ship. The players begin at the starting spaces, numbered I to VI. Movement is determined by the players by spending a set amount of gas (for the planes) or coal (for the ships), which is printed along each travel route. The players may either travel between to neighboring locations or between two locations which are not next to each other, but can be reached by spending a maximum of 24 units gas or 11 units coal. Gas and coal can be obtained by rolling two dies or by stopping by a location at which gas or coal can be restocked. The players can obtain merchandise by by flying to a harbor where the wanted merchandise is in stock and file a purchase option with the game master. The next step is to pick up the merchandise with the ship, before an other player too files an option and picks the merchandise up faster. The players have to pick up 12 different merchandise-cards before they are allowed to obtain gold at one of three possible locations. After obtaining gold, the players return to their starting space. The players may exchange merchandise, gas and coal according to their value. The first player to return his ship and his planes to his starting space ends and wins the game. The other players win 2nd to 6th place according to the value of their accumulated merchandise, gas, coal and gold.