Thunderbird is maintained by the Thunderbird Community, in cooperation with Mozilla Corporation, a wholly-owned subsidiary of the Mozilla Foundation. Thunderbird derives almost no revenue from search and other non-donor sources. Thunderbird relies heavily on the generous donations of users and friends of Thunderbird.
Thunderbird održava zajednica u saradnji sa Mozilla Corporation, podružnicom Mozilla Foundation. Thunderbird ne zarađuje praktično nikakve prihode od pretraživača i sličnih izvora. U velikoj mjeri zavisi od velikodušnih donacija Thunderbird korisnika i prijatelja.