At my last company (I quit a little over a year ago), we had a newsletter with a nice opt-in system setup (I set it up during my time there). 5000 active users I think and 30,000 users that had opted-out.
Well, at one of my last meetings, my boss yelled at me and told me that we were "leaving money on the table" by not sending emails to the opt-out list.
I explained to him exactly why it was a bad idea to email these people, but he didn't want to listen. Within a day we were permanently banned from our email provider.
My boss wanted to sue the mail provider for "disrupting our service". I've had so many terrible bosses that don't know how to run a proper business, I wonder how they make any money in the first place.
ME: According to the newsletter stats, more people have opted out than actually clicked on any links last week.
BOSS: We need to increase subscribers to the newsletter.