Thanks for responding.
I would like to make clear that my problem is complety general on my account. I've tested and my both characters (lvl 26 orc warrior and a Rogue lvl 23 Troll) are unable to communicate via Whisp, I'm able to send them, but people in general do not recieve them. I also notice that my posts on /world channel (general chat) are also "invisible", nobody is able to read it. I would like to believe that maybe was an blacklist problem, but it is strange, because people is able to read me if I /say, /yell or even chat whit them on /party chat. This just happens when I /whisper or post something in general channels like: /1, /2, /3, /world, etc.
As another detail, I would like to make clear that I play without addons on WoW Classic and my RLF who plays with me (it is thanks to him that I noticed this problem) use any addon either. I also tested with a familiar who recently began to play today (without any addon either) and he helped me to verify if this was just with my friend. He confirmed me that /party chats reached him, but whispers didn't.
If there's a possible reason for this I would like to know what it is to be able to fix it as soon as possible.
I'll wait for your response. Thanks for your time ๐