lib/PublicInbox/Filter.pm |  5 ++++-
 t/filter.t                | 20 ++++++++++++++++++++

diff --git a/lib/PublicInbox/Filter.pm b/lib/PublicInbox/Filter.pm
index 6cccd930862c363ab61393d05158e53ceb8b382a..a83ecc83088b696e71f24ab9d7d1f9ed8623c746 100644
--- a/lib/PublicInbox/Filter.pm
+++ b/lib/PublicInbox/Filter.pm
@@ -26,7 +26,10 @@
 	# kill potentially bad/confusing headers
 	# Note: ssoma already does this, but since we mangle the message,
 	# we should do this before it gets to ssoma.
-	foreach my $d (qw(status lines content-length)) {
+	# We also kill Mail-{Followup,Reply}-To and Reply-To headers due to
+	# the nature of public-inbox having no real subscribers.
+	foreach my $d (qw(status lines content-length
+			mail-followup-to mail-reply-to reply-to)) {
 		$simple->header_set($d);
 	}
 
diff --git a/t/filter.t b/t/filter.t
index 9c71b11f735a5bd7b6c8acd57f212ce9498edca6..12f4ed6f1f84e52ace60eab5591d23b8b38c7773 100644
--- a/t/filter.t
+++ b/t/filter.t
@@ -259,4 +259,24 @@ 	is(0, PublicInbox::Filter->run($f->simple), "run was a failure");
 	like($f->simple->as_string, qr/scrubbed/, "scrubbed message");
 }
 
+{
+	my $s = Email::Simple->create(
+		header => [
+			From => 'a@example.com',
+			To => 'b@example.com',
+			'Content-Type' => 'text/plain',
+			'Mail-Followup-To' => 'c@example.com',
+			Subject => 'mfttest',
+		],
+		body => "mft\n",
+	);
+
+	is('c@example.com', $s->header("Mail-Followup-To"),
+		"mft set correctly");
+	my $f = Email::Filter->new(data => $s->as_string);
+	is(1, PublicInbox::Filter->run($f->simple), "run succeeded for mft");
+	is(undef, $f->simple->header("Mail-Followup-To"), "mft stripped");
+}
+
+
 done_testing();