How can PHP be used to decode and convert confusing characters in email subjects for better readability?
Email subjects can sometimes contain confusing characters due to encoding issues. To decode and convert these characters for better readability in PHP, you can use the `mb_decode_mimeheader()` function. This function decodes MIME header elements that are encoded in a specific encoding scheme, such as quoted-printable or base64.
```php
$subject = '=?UTF-8?B?4p2k4p2h4p2p4p2kIOKWiOGLn+KWiOKWj+KWiOGLn+KWiOKWj+KWiOKWjyDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpDilpD