PHPMailer\PHPMailer

PHPMailer::isHTML() │ public │ WP 1.0

Sets message type to HTML or plain.

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

No Hooks.

Return

null. Nothing.

Usage

$PHPMailer = new PHPMailer();
$PHPMailer->isHTML( $isHtml );
$isHtml(true|false)
True for HTML mode
Default: true

Code of PHPMailer::isHTML() WP 6.0

wp-includes/PHPMailer/PHPMailer.php 
public function isHTML($isHtml = true)
{
    if ($isHtml) {
        $this->ContentType = static::CONTENT_TYPE_TEXT_HTML;
    } else {
        $this->ContentType = static::CONTENT_TYPE_PLAINTEXT;
    }
}