lib/PublicInbox/Filter.pm | 20 +++++---------------
 t/filter.t                |  2 ++

diff --git a/lib/PublicInbox/Filter.pm b/lib/PublicInbox/Filter.pm
index 0b4dce87a4a222c30fef8c6c887fc213b5f1b877..4a3482170422c7a16965a198abf89b7dac140d25 100644
--- a/lib/PublicInbox/Filter.pm
+++ b/lib/PublicInbox/Filter.pm
@@ -215,23 +215,13 @@ 	}
 	mark_changed($simple);
 }
 
-# run the file(1) command to detect mime type
-# Not using File::MMagic for now since that requires extra configuration
-# Note: we do not rewrite the message with the detected mime type
+# Check for display-able text, no messed up binaries
+# Note: we can not rewrite the message with the detected mime type
 sub recheck_type_ok {
 	my ($part) = @_;
-	my $cmd = "file --mime-type -b -";
-	my $pid = open2(my $out, my $in, $cmd);
-	print $in $part->body;
-	close $in;
-	my $type = eval {
-		local $/;
-		<$out>;
-	};
-	waitpid($pid, 0);
-	chomp $type;
-
-	(($type =~ $MIME_TEXT_ANY) && ($type !~ $MIME_HTML))
+	my $s = $part->body;
+	((bytes::length($s) < 0x10000) &&
+		($s =~ /\A([\P{XPosixPrint}\f\n\r\t]+)\z/))
 }
 
 1;
diff --git a/t/filter.t b/t/filter.t
index 0aa26a5f88977105857a804a8c90e226f40ceb66..ac9f1f6f973d42f4ac4cb56f7bf42ec536bde1b4 100644
--- a/t/filter.t
+++ b/t/filter.t
@@ -291,6 +291,8 @@ {
 	printf("Hello world\\n");
 	return 0;
 }
+
+/* some folks like ^L */
 EOF
 		),
 		Email::MIME->create(