“Emailing large numbers of employees about any topic not related to work is not appropriate. We have an established forum for employees who have opted in to political issues,” says Microsoft spokesperson Frank Shaw in a statement to The Verge. “Over the past couple of days, a number of politically focused emails have been sent to tens of thousands of employees across the company and we have taken measures to try and reduce those emails to those that have not opted in.”

Work email is a tool provided by the company to be used for work topics. Some employees are apparently using this tool to send unrelated emails to people who didn't sign up for it, but still have to deal with it somehow because they are probably required to check their email.

The company trying to reduce this seems reasonable to me, I'm surprised that so many people seem to take offense at it.