$str_s = '=?UTF-8?B?RndkOiDQntGE0LjRhtC40LDQu9GM0L3QvtC1INGB0L7RgtGA0YPQtNC90LjRh9C10YHRgg==?= во с Global Europe';
if(strpos($str_s, '=?UTF-8?B?') !== false){
$subjects_arr = explode("?=", $str_s);
foreach($subjects_arr as $subject_arr){
//(strpos($subject_arr, '=?UTF-8?B?') !== false)
if(strpos($subject_arr, '=?UTF-8?B?') !== false) {
trim($subject_arr, '=?UTF-8?B?');
$s_subject += base64_decode($subject_arr);
}else{
$s_subject += $subject_arr;
}
}
}else{
$s_subject = $str_s;
}
echo $s_subject;