Summary
From: MIMEエンコードされた日本語名 <user@example.com>From全体をMIMEエンコードしてはダメ!
Sample source
$mail_encoding = 'JIS';
$local_encoding = 'EUC-JP';
mb_language('Japanese');
mb_convert_variables($mail_encoding,$local_encoding,$name);
mb_convert_variables($mail_encoding,$local_encoding,$mail);
...
$from = mb_encode_mimeheader($name,$mail_encoding).' <'.$mail.'>';
$header = "From: $from\n";
$header .= "Cc: $cc\n";
$header .= "Bcc: $bcc\n";
mb_send_mail($to,$title,$contents,$header);