lib/PublicInbox/Mbox.pm | 6 +++++-

diff --git a/lib/PublicInbox/Mbox.pm b/lib/PublicInbox/Mbox.pm
index bc4d639ebad0809f3591cc38ecea7bb736039cb0..332e89a7220c1a153b764db42be8eb6846c97b08 100644
--- a/lib/PublicInbox/Mbox.pm
+++ b/lib/PublicInbox/Mbox.pm
@@ -42,7 +42,11 @@ 	$fh->write($buf .= $simple->crlf);
 
 	$buf = $simple->body;
 	$simple->body_set('');
-	$buf =~ s/^(From )/>$1/gm;
+
+	# mboxrd quoting style
+	# ref: http://www.qmail.org/man/man5/mbox.html
+	$buf =~ s/^(>*From )/>$1/gm;
+
 	$buf .= "\n" unless $buf =~ /\n\z/s;
 
 	$fh->write($buf);