The closing of schools at the beginning of spring 2020 in Greece highlighted the need for school distance education to make up for lost teaching time and to maintain learners’ contact with the educational process and other members of the school community. However, the teachers needed support in this urgent situation since they did not have previous experience in school distance education. The Laboratory for Advanced Teaching Technologies for Lifelong Learning and Distance Education (E-Learning Lab) of the University of Crete, attempted to contribute with its own means to the support of these teachers. Within this framework, fast-pace, distance seminars were designed and implemented to support teachers on pedagogical issues of distance education. A total of 20 distance training seminars were conducted from 19March to 29April2020 in which more than 40000 teachers of primary and secondary education in Greece participated. The overall presentation and assessment of the training actions showed not only the enormous interest of the teaching community but also the need for such training actions with particular emphasis on the principles and the methodology of school distance education, synchronous and asynchronous learning environments, and the designing or planning of teaching scenarios based on the pedagogical approaches compatible with distance learning.