lib/PublicInbox/IMAP.pm | 11 +++++++++--

diff --git a/lib/PublicInbox/IMAP.pm b/lib/PublicInbox/IMAP.pm
index 3cc68e668720814a9135ace5901ce43af2cf02c3..fe3c7d1a85bba20174642fb9399dce902bcdf0f8 100644
--- a/lib/PublicInbox/IMAP.pm
+++ b/lib/PublicInbox/IMAP.pm
@@ -792,6 +792,7 @@ 		$eml = eml_body_idx($eml, $section_idx) or return;
 	}
 	my $str = $eml->header_obj->as_string;
 	$str =~ s/$hdrs_re//g;
+	$str =~ s/(?<!\r)\n/\r\n/sg;
 	$str .= "\r\n";
 }
 
@@ -802,7 +803,9 @@ 	if (defined $section_idx) {
 		$eml = eml_body_idx($eml, $section_idx) or return;
 	}
 	my $str = $eml->header_obj->as_string;
-	join('', ($str =~ m/($hdrs_re)/g), "\r\n");
+	$str = join('', ($str =~ m/($hdrs_re)/g));
+	$str =~ s/(?<!\r)\n/\r\n/sg;
+	$str .= "\r\n";
 }
 
 sub partial_prepare ($$$$) {
@@ -828,7 +831,11 @@ 		my $tmp = $partial->{$att} = [ $2 ? \&partial_hdr_not
 						: \&partial_hdr_get,
 						$1, undef, $4, $5 ];
 		$tmp->[2] = hdrs_regexp($3);
-		$$need |= CRLF_HDR|EML_HDR;
+
+		# don't emit CRLF_HDR instruction, here, partial_hdr_*
+		# will do CRLF conversion with only the extracted result
+		# and not waste time converting lines we don't care about.
+		$$need |= EML_HDR;
 	} else {
 		undef;
 	}