Patch before ./configure, as otherwise mimedefang.pl will not have the
proper code below.

--- mimedefang.pl.in.orig       Fri Apr 25 06:16:11 2003
+++ mimedefang.pl.in    Thu Jun  5 19:14:37 2003
@@ -4763,14 +4763,15 @@
 #  base_url -- base URL for retrieving document
 #  msg -- message to replace document with.  The string "_URL_" is
 #         replaced with the actual URL of the part.
+#  cd_data -- optional Content-Disposition filename data to save
 # %RETURNS:
 #  1 on success, 0 on failure
 # %DESCRIPTION:
 #  Places the part in doc_root/{sha1_of_part}.ext and replaces it with
 #  a text/plain part giving the URL for pickup.
 #***********************************************************************
-sub action_replace_with_url ($$$$) {
-    my($entity, $doc_root, $base_url, $msg) = @_;
+sub action_replace_with_url ($$$$;$) {
+    my($entity, $doc_root, $base_url, $msg, $cd_data) = @_;
     my($ctx);
     my($path);
     my($fname, $ext, $name, $url);
@@ -4808,6 +4809,16 @@
        # In case umask is whacked...
        chmod 0644, $fname;
     }
+
+    # save optional Content-Disposition data
+    if ($cd_data) {
+      if (open CDF, ">$doc_root/.$name") {
+        print CDF $cd_data;
+        close CDF;
+        chmod 0644, "$doc_root/.$name";
+      }
+    }
+
     $msg =~ s/_URL_/$url/g;
     action_replace_with_warning($msg);
     return 1;
--- mimedefang-filter.5.in.orig Mon Apr 21 09:17:24 2003
+++ mimedefang-filter.5.in      Thu Jun  5 19:20:13 2003
@@ -861,6 +861,12 @@
 them.  If indexing is disabled, an attacker would have to guess the SHA1
 hash of a part in order to read it.
 
+Optionally, a fifth argument can supply data to be saved into a hidden
+dot filename based on the generated name.  This data can then be read in
+on the fly by a CGI script or mod_perl module before serving the file to
+a web client, and used to add information to the response, such as
+Content-Disposition data.
+
 .TP
 .B action_defang($entity, $name, $fname, $type)
 Accept the part, but change its name to \fI$name\fR, its suggested filename