Does anyone know how often other major e-mail service goes down? or do we only hear about it when gmail goes down? I don't remember yahoo mail going down or ho

Does anyone know how often other major e-mail service goes down? or do we only hear about it when gmail goes down? I don't remember yahoo mail going down or hotmail going down, at least, in the last couple of year. I think this is the third time gmail went down this year.