(PECL mailparse >= 0.9.0)
mailparse_stream_encode — Streams data from source file pointer, apply encoding and write to destfp
$sourcefp
   , resource $destfp
   , string $encoding      
   )
   Streams data from the source file pointer, apply 
   encoding and write to the destination file pointer. 
  
sourcefpA valid file handle. The file is streamed through the parser.
destfpThe destination file handle in which the encoded data will be written.
encodingOne of the character encodings supported by the mbstring module.
   Возвращает TRUE в случае успешного завершения  или FALSE в случае возникновения ошибки.
  
Пример #1 mailparse_stream_encode() example
<?php
// email.eml contents: hello, this is some text=hello.
$fp = fopen('email.eml', 'r');
$dest = tmpfile();
mailparse_stream_encode($fp, $dest, "quoted-printable");
rewind($dest);
// Display new file contents
fpassthru($dest);
?>
Результат выполнения данного примера:
hello, this is some text=3Dhello.