In Survivor, Tree Mail is a cryptic message the contestants receive before any game-related events such as challenges or other important events. Tree Mails also give out (commonly confusing) clues about upcoming twists and other events. The term may either pertain their mailbox or the message itself. There is also Tree Mail at Redemption Island.
There were some Tree Mails that were not related to challenges or Hidden Immunity Idols.
- In Survivor: Borneo, the Rattana tribe got a Tree Mail to inform them about Gervase Peterson's newborn son. ("Crack in the Alliance")
- In Survivor: The Australian Outback, Ogakor received a Tree Mail to inform them that an accident at Kucha had canceled the Immunity Challenge and Tribal Council. ("Trial by Fire")
- In Survivor: One World, Manono and Salani received a Tree Mail to inform them that the Immunity Challenge had been canceled, but that they had to proceed to Tribal Council that night. ("Thanks for the Souvenir")
- In Survivor: Millennials vs. Gen X, Takali and Vanua both received a Tree Mail to warn them about the approaching cyclone and to deliver a tarp for their camp. ("May the Best Generation Win")
- In Survivor: David vs. Goliath, following a cyclone, David and Goliath both received a Tree Mail which accompanied a fire-making kit and tarp. ("The Chicken Has Flown the Coop")
- In Survivor: Pearl Islands the tribes' mailbox is a treasure chest propped on a hull of a boat. The castaways jokingly called their Tree Mail, "sea mail", for their mail wasn't from a tree.
- Tracy Hughes-Wolf of Survivor: Micronesia smuggled two Tree Mail notes back home. This is a violation of the Survivor Rulebook.