When you are immune to the opinions and actions of others, you won’t be the victim of needless suffering.
in other words, don't take things personally!
I have just heard from a respected "friend" who asked me to take her off her email list.
I need to respect myself enough not to take it personally.
I am increasing my physical immune system by exercising regularly, eating well, rare alcohol, mindfulness, breathing consciously, and awareness.
Byron Katie's teaching is really good for increasing emotional/mental awareness.