lib/PublicInbox/Config.pm |  2 +-
 public-inbox-mda          | 13 ++++++++++++-

diff --git a/lib/PublicInbox/Config.pm b/lib/PublicInbox/Config.pm
index 315d788b8f3a508ed8fb53a03cafe2fdc1ad9812..0d73a867059f468c1e936d79d0a9a2102a5e3d61 100644
--- a/lib/PublicInbox/Config.pm
+++ b/lib/PublicInbox/Config.pm
@@ -61,7 +61,7 @@
 	defined $pfx or return;
 
 	my %rv;
-	foreach my $k (qw(mainrepo address)) {
+	foreach my $k (qw(mainrepo address filter)) {
 		my $v = $self->{"$pfx.$k"};
 		$rv{$k} = $v if defined $v;
 	}
diff --git a/public-inbox-mda b/public-inbox-mda
index 1a9469badfecd1c179601d5d7f7cba48b718ccc6..df8ca38c13ff3d93d59765e0dd5751dc45d599ee 100755
--- a/public-inbox-mda
+++ b/public-inbox-mda
@@ -38,7 +38,18 @@ 	my $msg = Email::MIME->new(\$filtered);
 	$filtered = undef;
 	$filter->simple($msg);
 
-	if (PublicInbox::Filter->run($msg, $filter)) {
+	my $filter_arg;
+	my $fcfg = $dst->{filter};
+	if (!defined $fcfg || $filter eq 'reject') {
+		$filter_arg = $filter;
+	} elsif ($fcfg eq 'scrub') {
+		$filter_arg = undef; # the default for legacy versions
+	} else {
+		warn "publicinbox.$dst->{listname}.filter=$fcfg invalid\n";
+		warn "must be either 'scrub' or 'reject' (the default)\n";
+	}
+
+	if (PublicInbox::Filter->run($msg, $filter_arg)) {
 		# run spamc again on the HTML-free message
 		if (do_spamc($msg, \$filtered)) {
 			$msg = Email::MIME->new(\$filtered);