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function is not described

PHPMailer\PHPMailer

PHPMailer::idnSupported() public WP 1.0

Tells whether IDNs (Internationalized Domain Names) are supported or not. This requires the intl and mbstring PHP extensions.

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

No Hooks.

Return

true|false. true if required functions for IDN support are present

Usage

$result = PHPMailer::idnSupported();

Code of PHPMailer::idnSupported() WP 5.7.2

<?php
public static function idnSupported()
{
    return function_exists('idn_to_ascii') && function_exists('mb_convert_encoding');
}