Index: Makefile.PL
===================================================================
--- Makefile.PL	(revision 54728)
+++ Makefile.PL	(working copy)
@@ -302,13 +302,67 @@
   warn $error;
 }
 
+my $check_cpan_p = 0;
 
+eval "use MIME::Base64;";
+if ($@) {
+  $check_cpan_p = 1;
+  print "\a",<<'MSG';
+  *** Note:
+      The optional MIME::Base64 module is not installed.  This module is highly
+      recommended to increase the speed with which Base64 encoded messages/mail
+      parts are decoded.
+
+MSG
+  sleep 2;
+}
+
+eval "use DB_File;";
+if ($@) {
+  $check_cpan_p = 1;
+  print "\a",<<'MSG';
+  *** Note:
+      The optional DB_File module is not installed.  DB_File is used to store data
+      on-disk for some SpamAssassin subsystems (Auto-Whitelist, Bayes, Hashcash, etc).
+
+MSG
+  sleep 2;
+}
+
+eval "use Net::DNS;";
+if ($@) {
+  $check_cpan_p = 1;
+  print "\a",<<'MSG';
+  *** Note:
+      The optional Net::DNS module is not installed.  The Net::DNS module is
+      used for all DNS-based tests (SBL, XBL, SpamCop, DSBL, etc.),
+      to perform MX checks, and is also used when manually reporting spam to
+      SpamCop.
+
+MSG
+  sleep 2;
+}
+
+if ($check_cpan_p) {
+    print <<'MSG';
+Optional modules are available from any CPAN mirror, in particular
+    http://search.cpan.org/
+    http://www.perl.com/CPAN/modules/by-module
+    http://www.perl.org/CPAN/modules/by-module
+    ftp://ftp.funet.fi/pub/languages/perl/CPAN/modules/by-module
+
+Once installed there is no reason to re-install SpamAssassin, they will be
+use automatically.
+
+MSG
+    sleep 4;
+}
+
 # All the $(*MAN1*) stuff is empty/zero if Perl was Configured with -Dman1dir=none
 unless($Config{installman1dir}) {
   delete $makefile{MAN1PODS};
 }
 
-
 # Windows platforms need some adjustments
 if (RUNNING_ON_WINDOWS) {
   # Don't build spamd