Description
string 
iconv_mime_encode ( string field_name, string field_value [, array preferences] )
     Composes and returns a string that represents a valid MIME
     header field, which looks like the following:
     
Subject: =?ISO-8859-1?Q?Pr=FCfung_f=FCr?= Entwerfen von einer MIME kopfzeile  | 
     In the above example, "Subject" is the field name and the portion that
     begins with "=?ISO-8859-1?..." is the field value.
    
     You can control the behaviour of iconv_mime_encode()
     by specifying an associative array that contains configuration items
     to the optional third parameter preferences.
     The items supported by iconv_mime_encode() are
     listed below. Note that item names are treated case-sensitive.
     
Table 1. Configuration items supported by iconv_mime_encode()
| Item | Type | Description | Default value | Example | 
|---|
| scheme | boolean | 
          Specifies the method to encode a field value by. The value of
          this item may be either "B" or "Q", where "B" stands for
          base64 encoding scheme and "Q" stands for
          quoted-printable encoding scheme.
          | B | B | 
| input-charset | string | 
          Specifies the character set in which the first parameter
          field_name and the second parameter
          field_value are presented. If not given,
          iconv_mime_encode() assumes those parameters
          are presented to it in the
          iconv.internal_charset
          ini setting.
          | 
          iconv.internal_charset
          | ISO-8859-1 | 
| output-charset | string | 
          Specifies the character set to use to compose the
          MIME header. If not given, the same value as
          input-charset will be used.
          | 
          the same value as input-charset
          | UTF-8 | 
| line-length | integer | 
          Specifies the maximum length of the header lines. The resulting
          header is "folded" to a set of multiple lines in case
          the resulting header field would be longer than the value of this
          parameter, according to
          RFC2822 - Internet Message Format.
          If not given, the length will be limited to 76 characters.
          | 76 | 996 | 
| line-break-chars | string | 
          Specifies the sequence of characters to append to each line
          as an end-of-line sign when "folding" is performed on a long header
          field. If not given, this defaults to "\r\n"
          (CR LF). Note that
          this parameter is always treated as an ASCII string regardless
          of the value of input-charset.
          | \r\n | \n | 
 
    Example 1. iconv_mime_encode() example: 
<?php $preferences = array(     "input-charset" => "ISO-8859-1",     "output-charset" => "UTF-8",     "line-length" => 76,     "line-break-chars" => "\n" ); $preferences["scheme"] = "Q"; // This yields "Subject: =?UTF-8?Q?Pr=C3=BCfung_Pr=C3=BCfung?=" echo iconv_mime_encode("Subject", "Prüfung Prüfung", $preferences);
  $preferences["scheme"] = "B"; // This yields "Subject: =?UTF-8?B?UHLDvGZ1bmcgUHLDvGZ1bmc=?=" echo iconv_mime_encode("Subject", "Prüfung Prüfung", $preferences); ?>
 |  
  | 
     See also imap_binary(),
     mb_encode_mimeheader()
     and imap_8bit().