Are you overreacting? In my opinion, depending on how long the suspension lasts, you may be, though not necessarily. You sent unsolicited bulk e-mail. That is spam. It is possible that your mail helped some people, but anyone who had set up their own filtering to prevent the original mail from coming through would then only see it because of your followup, and additionally the "To" list may well have been spoofed as well and not reflect who the original mail was actually sent to. Google have a responsibility to prevent spam from being sent through their systems, and if this suspension is the minimal they can do to stop your spam, it was the right thing for Google to do, and you would see the same with a lot of other e-mail providers as well. However, if this suspension lasts beyond the point where you are clearly aware of it and can make sure you do not repeat that, then no, as far as I am concerned you will no longer be overreacting and should look to avoid Google in the future.