diff --git a/git-send-email.perl b/git-send-email.perl
index 288ea1ae80..bbda2a931b 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -888,73 +888,59 @@ sub get_patch_subject {
 		do_edit($compose_filename);
 	}
 
+	open my $c2, ">", $compose_filename . ".final"
+		or die sprintf(__("Failed to open %s.final: %s"), $compose_filename, $!);
+
 	open $c, "<", $compose_filename
 		or die sprintf(__("Failed to open %s: %s"), $compose_filename, $!);
 
+	my $need_8bit_cte = file_has_nonascii($compose_filename);
+	my $in_body = 0;
+	my $summary_empty = 1;
 	if (!defined $compose_encoding) {
 		$compose_encoding = "UTF-8";
 	}
-
-	my %parsed_email;
-	while (my $line = <$c>) {
-		next if $line =~ m/^GIT:/;
-		parse_header_line($line, \%parsed_email);
-		if ($line =~ /^$/) {
-			$parsed_email{'body'} = filter_body($c);
+	while(<$c>) {
+		next if m/^GIT:/;
+		if ($in_body) {
+			$summary_empty = 0 unless (/^\n$/);
+		} elsif (/^\n$/) {
+			$in_body = 1;
+			if ($need_8bit_cte) {
+				print $c2 "MIME-Version: 1.0\n",
+					 "Content-Type: text/plain; ",
+					   "charset=$compose_encoding\n",
+					 "Content-Transfer-Encoding: 8bit\n";
+			}
+		} elsif (/^MIME-Version:/i) {
+			$need_8bit_cte = 0;
+		} elsif (/^Subject:\s*(.+)\s*$/i) {
+			$initial_subject = $1;
+			my $subject = $initial_subject;
+			$_ = "Subject: " .
+				quote_subject($subject, $compose_encoding) .
+				"\n";
+		} elsif (/^In-Reply-To:\s*(.+)\s*$/i) {
+			$initial_in_reply_to = $1;
+			next;
+		} elsif (/^Reply-To:\s*(.+)\s*$/i) {
+			$reply_to = $1;
+		} elsif (/^From:\s*(.+)\s*$/i) {
+			$sender = $1;
+			next;
+		} elsif (/^(?:To|Cc|Bcc):/i) {
+			print __("To/Cc/Bcc fields are not interpreted yet, they have been ignored\n");
+			next;
 		}
+		print $c2 $_;
 	}
 	close $c;
+	close $c2;
 
-	open my $c2, ">", $compose_filename . ".final"
-	or die sprintf(__("Failed to open %s.final: %s"), $compose_filename, $!);
-
-
-	if ($parsed_email{'From'}) {
-		$sender = delete($parsed_email{'From'});
-	}
-	if ($parsed_email{'In-Reply-To'}) {
-		$initial_in_reply_to = delete($parsed_email{'In-Reply-To'});
-	}
-	if ($parsed_email{'Reply-To'}) {
-		$reply_to = delete($parsed_email{'Reply-To'});
-	}
-	if ($parsed_email{'Subject'}) {
-		$initial_subject = delete($parsed_email{'Subject'});
-		print $c2 "Subject: " .
-			quote_subject($initial_subject, $compose_encoding) .
-			"\n";
-	}
-
-	if ($parsed_email{'MIME-Version'}) {
-		print $c2 "MIME-Version: $parsed_email{'MIME-Version'}\n",
-				"Content-Type: $parsed_email{'Content-Type'};\n",
-				"Content-Transfer-Encoding: $parsed_email{'Content-Transfer-Encoding'}\n";
-		delete($parsed_email{'MIME-Version'});
-		delete($parsed_email{'Content-Type'});
-		delete($parsed_email{'Content-Transfer-Encoding'});
-	} elsif (file_has_nonascii($compose_filename)) {
-		my $content_type = (delete($parsed_email{'Content-Type'}) or
-			"text/plain; charset=$compose_encoding");
-		print $c2 "MIME-Version: 1.0\n",
-			"Content-Type: $content_type\n",
-			"Content-Transfer-Encoding: 8bit\n";
-	}
-	# Preserve unknown headers
-	foreach my $key (keys %parsed_email) {
-		next if $key eq 'body';
-		print $c2 "$key: $parsed_email{$key}";
-	}
-
-	if ($parsed_email{'body'}) {
-		print $c2 "\n$parsed_email{'body'}\n";
-		delete($parsed_email{'body'});
-	} else {
+	if ($summary_empty) {
 		print __("Summary email is empty, skipping it\n");
 		$compose = -1;
 	}
-
-	close $c2;
-
 } elsif ($annotate) {
 	do_edit(@files);
 }
@@ -1009,32 +995,6 @@ sub ask {
 	return;
 }
 
-sub parse_header_line {
-	my $lines = shift;
-	my $parsed_line = shift;
-	my $addr_pat = join "|", qw(To Cc Bcc);
-
-	foreach (split(/\n/, $lines)) {
-		if (/^($addr_pat):\s*(.+)$/i) {
-		        $parsed_line->{$1} = [ parse_address_line($2) ];
-		} elsif (/^([^:]*):\s*(.+)\s*$/i) {
-		        $parsed_line->{$1} = $2;
-		}
-	}
-}
-
-sub filter_body {
-	my $c = shift;
-	my $body = "";
-	while (my $body_line = <$c>) {
-		if ($body_line !~ m/^GIT:/) {
-			$body .= $body_line;
-		}
-	}
-	return $body;
-}
-
-
 my %broken_encoding;
 
 sub file_declares_8bit_cte {
diff --git a/t/t9001-send-email.sh b/t/t9001-send-email.sh
index 263db3ad17..9644ff5793 100755
--- a/t/t9001-send-email.sh
+++ b/t/t9001-send-email.sh
@@ -2505,4 +2505,39 @@ test_expect_success $PREREQ 'test forbidSendmailVariables behavior override' '
 		HEAD^
 '
 
+test_expect_success $PREREQ '--compose handles lowercase headers' '
+	write_script fake-editor <<-\EOF &&
+	sed "s/^From:.*/from: edited-from@example.com/i" "$1" >"$1.tmp" &&
+	mv "$1.tmp" "$1"
+	EOF
+	clean_fake_sendmail &&
+	git send-email \
+		--compose \
+		--from="Example <from@example.com>" \
+		--to=nobody@example.com \
+		--smtp-server="$(pwd)/fake.sendmail" \
+		HEAD^ &&
+	grep "From: edited-from@example.com" msgtxt1
+'
+
+test_expect_success $PREREQ '--compose handles to headers' '
+	write_script fake-editor <<-\EOF &&
+	sed "s/^$/To: edited-to@example.com\n/" <"$1" >"$1.tmp" &&
+	echo this is the body >>"$1.tmp" &&
+	mv "$1.tmp" "$1"
+	EOF
+	clean_fake_sendmail &&
+	GIT_SEND_EMAIL_NOTTY=1 \
+	git send-email \
+		--compose \
+		--from="Example <from@example.com>" \
+		--to=nobody@example.com \
+		--smtp-server="$(pwd)/fake.sendmail" \
+		HEAD^ &&
+	# Ideally the "to" header we specified would be used,
+	# but the program explicitly warns that these are
+	# ignored. For now, just make sure we did not abort.
+	grep "To:" msgtxt1
+'
+
 test_done
