The Red Mail is the ultimate in Hyrulian battle protection. It's fashionable, too. Link will be all the rage. "
The Red Mail is an optional tunic found in both A Link to the Past and its indirect sequel, A Link Between Worlds. It is red in color, and is the best tunic available to Link. It is very similar in appearance to the Goron Tunic, an item found exclusively in Ocarina of Time.
A Link to the Past
The Red Mail in A Link to the Past is found within Ganon's Tower. It reduces damage by ¼ over the Green Jerkin and ½ over the Blue Mail. Although the Red Mail is not required to complete the game, it helps considerably with the rest of Ganon's Tower and the fight with Ganon himself.
The chest containing the Red Mail is found on the first floor of Ganon's Tower, just north of the large square room. However, the chest is locked, and requires the Big Key to open. This key is found on the Basement floor, and thus Link needs to access that area before he can acquire the Mail. Once Link has reached the Basement floor, he finds himself in a Mini-Boss fight with the Armos Knights, a re-appearing Boss from the Eastern Palace. Once Link has defeated the Knights, he can head up a room to find a chest that contains the Big Key. With the key in hand, Link can return to the first floor and retrieve the Red Mail
A Link Between Worlds
The Red Mail is found in Lorule Castle in A Link Between Worlds. It is the final mail Link receives. Similarly to its A Link to the Past counterpart, the Red Mail reduces damage by 3/4 over the Green Mail, as well as ½ over the Blue Mail. The Red Mail is not required to complete the game, though it is extremely useful during the final battles.
It is found in a large Treasure Chest on the fourth floor of the castle. However, it is hidden on an isolated platform with no visible way of reaching it. However, if Link extinguishes the torches within the area, two thin bridges appear, allowing Link to reach the platform.