Re: Boss situation again
My own opinion of him sinks lower with each new revelation. He's a coward.
But, in my opinion, he's also making a big mistake by making these criticisms in writing. The approach might depend on whether you have any fear that they could ultimately fire you. I'll explain:
If you begin to save these emails, and print a copy to save at home, if you are ever fired, you can use these to build a case that your boss is creating a hostile environment, at least in many states. If you were denied unemployment, most states have a review process for contesting. You just explain your side at the labor board. The decisions often boil down to a short hearing, and if your agent at the labor board brought in your evidence, and this did not match the seriousness of past performance reviews, often unemployment can be awarded. At least in the states where I had such situations.
But, if your goal is just to end the critical emails, another approach might work. Only you would know if it may work with your boss, though. You can save these emails from him, and print a copy. One day, ask if you can speak to the boss about a serious matter. Bring another copy of the emails (an extra copy) with the critical comments highlighted. Have them in a hanging folder, because anyone would make the connection that you are saving them.
You can take the approach of just telling him that you take your job performance very seriously. You want to improve. You want to be able to make sure that he is completely happy with your performance. If he has half a brain, the emails would stop, because he'll realize that emailing those types of comments is stupid. He may ask why you are saving them. You can remind him that you take your performance very seriously, and the only way to do so is to use constructive criticism like this in order to make sure you improve your skills so that it never happens again.
Problem is, if you work in an environment where people have no training in labor laws and best practices, my only fear is that this could escalate into a more serious issue that makes you even more miserable. In many places, however, the supervisor will realize that every email is going into that deep dark hanging folder you maintain. In one location in my past, I was a mentor to the supervisors across the location because they were all relatively new. I met with them weekly and required them to discuss their interactions with their employees. So many times, I saw cases like your boss and warned them that they were hanging themselves by their own ignorance.
Just a few thoughts.