Ok , the problem is that i named my mail as mail.example.cl (where i did my zimbra installation) , i have created some accounts to test, and i can send and receive mail without any problem.
Then i created another new domain (lets call it test.cl), i can send mail to multiple accounts (gmail, hotmail, etc) , but the problem is that i cannot receive mails from other mail accounts.
the error that it gives me is rcpt , user unknown.
its not a connectivity problem i guess, because if it says that there is no user knowed, its because it can query the server from the internet.
so the problem must be another thing.
i have mx & a records in my dns for this new domain , so probably is not a dns problem.
thanks for your help