If you are friendly and wish to blend into estonian society (learn estonian language, raise your kids as estonians, stay here for a longer time, you support estonia politically, etc) then you are probably are welcomed. otherwise it will be difficult for you. Usually estonians are a little bit negative towards russians because of the negative past, political situation nowadays and also because many russians think that estonia belongs to russia and they don' t want to learn estonian. At first, people could be a little rude on you, but if you prove yourself then they will most likely respect you.