When should we give a man the silent treatment and when should we pour out our heart?

Silence is sometimes the tool of choice when a man has behaved badly towards you, and then is attempting to re- engage you.

If your relationship failed because he betrayed you, raged at you, abandoned you or mistreated you in any way.
If you perceived that you were dealing with a narcissist or a borderline disordered man, and decided to break it off, then the best thing to do is to remain silent.

Know that his efforts to communicate with you post break up are most probably due to his need to manipulate your emotions so that you remain vulnerable to him. Power over you is the food his weak ego craves. The best thing to do is to starve it and to remain silent.

Do not empower him nor get pulled back into his destructive orb.

We are not talking hear about the normal and natural ups and downs or occasional out bursts that occur in  any normal relationship. We are speaking specifically of a situation where you have left a relationship that was toxic to you because your man was unhealthy emotionally and took it out on you, was unfaithful or abusive. This man may very likely reach out to you after a break up, even if he is now in another relationship! He may try to keep a Chanel of communication open with you, remain "friends" or try to re establish the relationship, just when you are finally healing from the emotional wounds he inflicted upon you.

Please know that he does not deserve the gratification of your attentions. Don't try to pour out your heart to him, explain yourself to him or offer him an empathetic ear.
Know that he has a need to feel that he still has some power and influence over you, and this is something that he does not deserve.
Keep Silent.
Let his calls go to Voice Mail.
Block him.