The Estate is lashing out after HBO announced "Leaving Neverland" will be broadcast on March 3 and 4.

The Estate's letter to HBO targets director Dan Reed, claiming he featured 2 admitted perjurers -- Wade Robson and James Safechuck -- and consciously refused to contact anyone who would discredit them. And, the letter makes it clear -- there are plenty of people who do just that.

The letter says, "The Estate spent years litigating with Robson and Safechuck, and had four different lawsuits by these two men dismissed with prejudice. Today, Robson owes the Estate almost seventy thousand dollars in court costs, and Safechuck owes the Estate thousands of dollars as well."

And, the letter goes on, noting that following MJ's 2009 death, Robson said Michael was "one of the main reasons I believe in the pure goodness of human kind."

As for why Robson changed his story ... the Estate reiterated what it's said before, that he became angry when the Estate rejected him as a choreographer for the MJ-themed Cirque de Soleil.

And, the letter says, "Robson is such a good liar that his own mother testified under oath at her deposition that she could not tell when he was lying; she even volunteered that 'he should have had an Oscar given how convincing his lies were.'"

The Estate blasts Safechuck, scoffing at claims that his memory of abuse was triggered when he saw Robson on the "Today" show, adding, "Safechuck's frivolous lawsuits were dismissed so early in the proceedings that significant discovery was never taken ..."