Since 1994 he was Head of the Centre for Oriental Studies, senior research fellow, Department of History, Faculty of Philosophy, University of Tartu.
Later he was dismissed for anti-communist views and subsequently worked for ten years as engineer of the Cabinet for Oriental Studies.
Mäll was inspired to become a Buddhist and buddhologist by well-known Estonian theologian and philosopher Uku Masing in the early 1960s.
He later studied under and worked together with several Buddhist and non-Buddhist teachers and scholars including Nikolai Konrad, Alexander Piatigorsky, Oktiabrina Volkova, Youri Parfionovich, Lev Menshikov and Lama Bidia Dandaron.
He was awarded the Order of the White Star, IV degree in 2001, and the Medal of Freedom of the Government of the Chechen Republic of Ichkeria in exile in March 2004.