The worst is when your own employer starts spamming your email with useless crap. I would get several emails a day from HR or some other group about some event coming up that I had zero interest in nor asked to be notified of. Don’t forget to sign up for XYZ, check out what your colleagues are saying in Stupid Internal Social Network, and so on.

And worst of all, every “extra-cirricular” group was allowed to abuse the company-wide mailing list to promote their softball games or trivia or whatever else.