Use mb_encode_mimeheader() / iconv_mime_encode()

http://www.php.net/mb_encode_mimeheader
http://www.php.net/iconv_mime_encode.

just RTFM.

iconv_mime_encode would be nearly fine for me
(until I don't use multy-byte) except that it
writes "Subject: blah" a la SMTP. I will have
to remove the leading "Subject: ", [raw]urlencode
the "blah" and append the result to the url,
after an "&Subject=". And will I trust using
substr($iconverted,9) or should I use a regex
to match the colon?

Please... :-) Nasty as national chars in headers are,
if at least they could be used correctly life might
be better. And since much html is created using
PHP and url-functions, a well documented dedicated
function may improve overall conformancy. In facts
many programmers --I for one-- are not sure what is
the correct encoding of a mailto tags among the three
on my test page.

BTW, why configure doesn't include iconv automatically?

Thanks
Ale