The laws of the prohibition of “Lashon Hara” – gossip.
1. The Torah strictly forbids gossiping. This prohibition concerns even if what is said is absolutely true. Our sages consider Lashon Hara as one of the worst of transgressions, saying, that he, who multiplies rumors, loses his part in the future world. It is also prohibited to listen to someone else, speaking Lashon Hara, and if one overhears it, it is forbidden to believe what he hears.
2. When we are asked, “Who did such an awful thing?” or “Who wished me this harm?” it is forbidden to answer. There are exceptions, for instance, where our answer can resume justice or help in somebody’s education, one may give an answer. Besides, in a situation, where fairness is required, one may tell about other’s transgression, even if nobody asked him to. Nevertheless, in each case one should consult a Rabbi, because there are various conditions for revealing the information.
3. Saying Lashon Hara is still a prohibited even if one telling something pretends he didn’t mean to hurt anyone, or if he only hints his point. For example, “Who could have thought that he would become so smart” – implying that he used to be stupid, “At least he has this good quality” – meaning he is no good in all other ways. It can happen that one violates the prohibition for Lashon Hara even using specific intonations in his voice: “those people are cooking all the time”. It is forbidden to say something good about someone in front of his enemies, because his enemies are then likely to say something bad.
4. We are forbidden to say Lashon Hara even when someone in question is present. The prohibition against gossiping apply regardless of who we are speaking to – one may not say Lashon Hara to his spouse or to his parents.
5. The Torah allows saying unpleasant things to warn others. For instance if we know that one wants to marry a certain girl who possesses certain bad qualities or illnesses that can harm their marriage, we should warn the fiancé. The same concerns one, who is taking a new business partner. But still, we cannot judge what can be considered a serious drawback, and in each and every case one should consult a Rabbi. (Chofetz Chaim gives us an example of a fiancé for whom the Torah is not his strongest point. It is forbidden to tell this fact to his prospective bride if she hasn’t made an attempt to find out about this herself. In fact, many women don’t stress upon the level of their husbands’ knowledge. But if she asked about it, one can tell the truth.) Even when hearing an important piece of information, one should not fully believe it, one is only allowed to account for a possibility that the information could be true. And still, if one finds out something, he should not act right away. For example, if after the “vort” (engagement) the fiancé found out something not really attractive about the prospective bride, only a knowledgeable Rabbi can decide, whether this information is sufficient to break the engagement. Moreover, if someone who tells knows for sure that his listener will not consult a Rabbi and will break his engagement then this someone should keep this information to himself and not tell it. At any rate, as we mentioned there are specific condition that need to be met in order that one can reveal the information, so each case should be discussed with a Rabbi.