PHPMailer::punyencodeAddress( string $address ): string

1613    public function punyencodeAddress($address)1614    {1615        //Verify we have required functions, CharSet, and at-sign.1616        $pos = strrpos($address, '@');1617        if (1618            !empty($this->CharSet) &&1619            false !== $pos &&1620            static::idnSupported()1621        ) {1622            $domain = substr($address, ++$pos);1623            //Verify CharSet string is a valid one, and domain properly encoded in this CharSet.1624            if ($this->has8bitChars($domain) && @mb_check_encoding($domain, $this->CharSet)) {1625                //Convert the domain from whatever charset it's in to UTF-81626                $domain = mb_convert_encoding($domain, self::CHARSET_UTF8, $this->CharSet);1627                //Ignore IDE complaints about this line - method signature changed in PHP 5.41628                $errorcode = 0;1629                if (defined('INTL_IDNA_VARIANT_UTS46')) {1630                    //Use the current punycode standard (appeared in PHP 7.2)1631                    $punycode = idn_to_ascii(1632                        $domain,1633                        \IDNA_DEFAULT | \IDNA_USE_STD3_RULES | \IDNA_CHECK_BIDI |1634                            \IDNA_CHECK_CONTEXTJ | \IDNA_NONTRANSITIONAL_TO_ASCII,1635                        \INTL_IDNA_VARIANT_UTS461636                    );1637                } elseif (defined('INTL_IDNA_VARIANT_2003')) {1638                    //Fall back to this old, deprecated/removed encoding1639                    // phpcs:ignore PHPCompatibility.Constants.RemovedConstants.intl_idna_variant_2003DeprecatedRemoved1640                    $punycode = idn_to_ascii($domain, $errorcode, \INTL_IDNA_VARIANT_2003);1641                } else {1642                    //Fall back to a default we don't know about1643                    // phpcs:ignore PHPCompatibility.ParameterValues.NewIDNVariantDefault.NotSet1644                    $punycode = idn_to_ascii($domain, $errorcode);1645                }1646                if (false !== $punycode) {1647                    return substr($address, 0, $pos) . $punycode;1648                }1649            }1650        }1651 1652        return $address;1653    }