(PHP 4, PHP 5, PHP 7, PHP 8)
imap_utf8 — Converts MIME-encoded text to UTF-8
$mime_encoded_text): string
   Converts the given mime_encoded_text to
   UTF-8, if the declared charset is known to libc-client.
   Otherwise the given text is decoded, but not converted to UTF-8.
  
Returns the decoded string, if possible converted to UTF-8.
Example #1 Basic imap_utf8() Usage
<?php
echo imap_utf8("Johannes =?ISO-8859-1?Q?Schl=FCter?=");
?>
The above example will output something similar to:
Johannes Schlüter