WordPress at a glance
function is not described

PHPMailer\PHPMailer

PHPMailer::clearCustomHeaders() public WP 1.0

Clear all custom headers.

{} It's a method of the class: PHPMailer{}

No Hooks.

Return

null. Nothing.

Usage

$PHPMailer = new PHPMailer();
$PHPMailer->clearCustomHeaders();

Code of PHPMailer::clearCustomHeaders() WP 5.7.2

<?php
public function clearCustomHeaders()
{
    $this->CustomHeader = [];
}