The Rafflesia, why does it smell?

Rafflesia is a genus of parasitic flowering plants, all found in the SouthEastern part of Asia, on the Malay Peninsula, Borneo, Sumatra and Kalimantan, West Malaysia and the Philippines. The plant has no stems, leaves or true roots. The only part of the plant that can be seen outside the host vine is the 5-petaled flower. The flower look and smell like rotting meat, hence the local names which translates to "corpse flower" or "meat flower".
The vile smell that the flower gives off attracts insects such as Carrion flies, which transport pollen from male to female flowers.
. However, tree shrews and other forest mammals apparently eat the fruits and disperse the seeds. Rafflesia is an official state flower of Sabah in Malaysia, as well as for the Surat Thani Province of Thailand.