The last public photograph of Mr. Perlmutter was taken in 1985, despite his being Marvel's chief executive and one of Disney's largest individual shareholders. He has never given an interview to the media while running Marvel, despite the Disney unit's influence over American entertainment with its Iron Man, Captain America and X-Men franchises.
Mr. Perlmutter's lawyer, as you might imagine, has denied he had anything to do with the letters. He has contended the case is a shakedown and suggests that Mr. Peerenboom, a Toronto businessman who founded a successful executive search firm, is a serial litigator.
Mr. Peerenboom's side says that the evidence is clear and convincing. His case has withstood multiple efforts to have it dismissed; in each instance, a judge has said that there is enough evidence to proceed.
The story took a particularly strange turn last year when Mr. Peerenboom's legal team said that a private lab had found a direct DNA match on the outside of one of the sent envelopes, implicating Mr. Perlmutter's wife, Laura.
Mr. Perlmutter's lawyers say that the DNA evidence was planted and is inadmissible in court. The lawyers contend that Mr. Peerenboom's legal team stole DNA samples from water bottles and papers that the Perlmutters used and touched during a deposition.
Both sides have hired high-powered lawyers. Mr. Perlmutter retained Roy Black, who helped William Kennedy Smith successfully defend against rape charges in Palm Beach. Mr. Peerenboom hired the New York litigator Marc E. Kasowitz, who has represented Donald J. Trump.
At the center of the case is Karen D. Donnelly, who ran the tennis program inside the Sloans Curve community. She was a favorite of Mr. Perlmutter, an avid tennis player.
Mr. Peerenboom, who moved into the community in 2007, learned that Ms. Donnelly worked without a contract and had not bid for the work, which he claimed amounted to bid-rigging under Florida law. He made his objection to the arrangement known to the homeowners' organization. But the board, nudged by Mr. Perlmutter, overruled Mr. Peerenboom and reworked the agreement with Ms. Donnelly so she didn't have to submit a competitive bid to run the tennis complex.
Ms. Donnelly then filed a lawsuit against Mr. Peerenboom and others — paid for by Mr. Perlmutter — contending she had been slandered.
Then the hate-letter writing campaign began, Mr. Peerenboom says, coinciding with specific efforts to have Ms. Donnelly removed.