- mb_decode_mimeheader: documentation ( source)
- mb_internal_encoding: documentation ( source)
<?php
mb_internal_encoding('ISO-8859-1');
echo 'Subject: ', mb_decode_mimeheader('=?UTF-8?B?w5DCncOQwr7DkMKyw5HCi8OQwrkgw5DCssOQwr7DkMK/w5E=?= =?UTF-8?B?woDDkMK+w5HCgSDDkMK9w5DCsCDDkcKBw5DCsMOQwrnDkcKCw5DCtSA=?= =?UTF-8?B?Y3JlZGl0Y2FyZHNvbmxpbmUucnU=?=');