1. It is forbidden to speak or accept lashon hara. The sin of one who accepts lashon hara is greater than that of the speaker, even when he doesn’t say outright that he has accepted the lashon hara.

2. Even when one doesn’t accept the words of lashon hara, it is still forbidden to listen to them, unless he does so for a good reason, for instance, he’s considering a potential  business partnership with the subject, and hearing something negative about him will cause him to think twice. However, even in such cases, it is permitted only to listen and perhaps act on it or look into the matter, but not to believe it as fact.