diff --git a/Documentation/githooks.txt b/Documentation/githooks.txt
index a16e62bc8c..346e536cbe 100644
--- a/Documentation/githooks.txt
+++ b/Documentation/githooks.txt
@@ -583,10 +583,10 @@ processed by rebase.
 sendemail-validate
 ~~~~~~~~~~~~~~~~~~
 
-This hook is invoked by linkgit:git-send-email[1].  It takes a single parameter,
-the name of the file that holds the e-mail to be sent.  Exiting with a
-non-zero status causes `git send-email` to abort before sending any
-e-mails.
+This hook is invoked by linkgit:git-send-email[1].  It takes two parameters,
+the name of a file that holds the patch and the name of a file that holds the
+SMTP headers.  Exiting with a non-zero status causes `git send-email` to abort
+before sending any e-mails.
 
 fsmonitor-watchman
 ~~~~~~~~~~~~~~~~~~
diff --git a/git-send-email.perl b/git-send-email.perl
index 5861e99a6e..5a626a4238 100755
--- a/git-send-email.perl
+++ b/git-send-email.perl
@@ -787,14 +787,6 @@ sub is_format_patch_arg {
 
 @files = handle_backup_files(@files);
 
-if ($validate) {
-	foreach my $f (@files) {
-		unless (-p $f) {
-			validate_patch($f, $target_xfer_encoding);
-		}
-	}
-}
-
 if (@files) {
 	unless ($quiet) {
 		print $_,"\n" for (@files);
@@ -1495,16 +1487,7 @@ sub file_name_is_absolute {
 	return File::Spec::Functions::file_name_is_absolute($path);
 }
 
-# Prepares the email, then asks the user what to do.
-#
-# If the user chooses to send the email, it's sent and 1 is returned.
-# If the user chooses not to send the email, 0 is returned.
-# If the user decides they want to make further edits, -1 is returned and the
-# caller is expected to call send_message again after the edits are performed.
-#
-# If an error occurs sending the email, this just dies.
-
-sub send_message {
+sub gen_header {
 	my @recipients = unique_email_list(@to);
 	@cc = (grep { my $cc = extract_valid_address_or_die($_);
 		      not grep { $cc eq $_ || $_ =~ /<\Q${cc}\E>$/ } @recipients
@@ -1546,6 +1529,22 @@ sub send_message {
 	if (@xh) {
 		$header .= join("\n", @xh) . "\n";
 	}
+	my $recipients_ref = \@recipients;
+	return ($recipients_ref, $to, $date, $gitversion, $cc, $ccline, $header);
+}
+
+# Prepares the email, then asks the user what to do.
+#
+# If the user chooses to send the email, it's sent and 1 is returned.
+# If the user chooses not to send the email, 0 is returned.
+# If the user decides they want to make further edits, -1 is returned and the
+# caller is expected to call send_message again after the edits are performed.
+#
+# If an error occurs sending the email, this just dies.
+
+sub send_message {
+	my ($recipients_ref, $to, $date, $gitversion, $cc, $ccline, $header) = gen_header();
+	my @recipients = @$recipients_ref;
 
 	my @sendmail_parameters = ('-i', @recipients);
 	my $raw_from = $sender;
@@ -1955,6 +1954,15 @@ sub process_file {
 		}
 	}
 
+
+	if ($validate) {
+		foreach my $f (@files) {
+			unless (-p $f) {
+				validate_patch($f, $target_xfer_encoding);
+			}
+		}
+	}
+
 	my $message_was_sent = send_message();
 	if ($message_was_sent == -1) {
 		do_edit($t);
@@ -2088,11 +2096,20 @@ sub validate_patch {
 			chdir($repo->wc_path() or $repo->repo_path())
 				or die("chdir: $!");
 			local $ENV{"GIT_DIR"} = $repo->repo_path();
+
+			my ($recipients_ref, $to, $date, $gitversion, $cc, $ccline, $header) = gen_header();
+
+			require File::Temp;
+			my ($header_filehandle, $header_filename) = File::Temp::tempfile(
+                            ".gitsendemail.header.XXXXXX", DIR => $repo->repo_path());
+			print $header_filehandle $header;
+
 			my @cmd = ("git", "hook", "run", "--ignore-missing",
 				    $hook_name, "--");
 			my @cmd_msg = (@cmd, "<patch>");
-			my @cmd_run = (@cmd, $target);
+			my @cmd_run = (@cmd, $target, $header_filename);
 			$hook_error = system_or_msg(\@cmd_run, undef, "@cmd_msg");
+			unlink($header_filehandle);
 			chdir($cwd_save) or die("chdir: $!");
 		}
 		if ($hook_error) {
diff --git a/t/t9001-send-email.sh b/t/t9001-send-email.sh
index 1130ef21b3..11e68f9c18 100755
--- a/t/t9001-send-email.sh
+++ b/t/t9001-send-email.sh
@@ -565,6 +565,31 @@ test_expect_success $PREREQ "--validate respects absolute core.hooksPath path" '
 	test_cmp expect actual
 '
 
+test_expect_success $PREREQ "--validate hook supports header argument" '
+	test_when_finished "rm my-hooks.ran" &&
+	write_script my-hooks/sendemail-validate <<-\EOF &&
+	filesize=$(stat -c%s "$2")
+	if [ "$filesize" != "0" ]; then
+	>my-hooks.ran
+	fi
+	exit 1
+	EOF
+	test_config core.hooksPath "my-hooks" &&
+	test_must_fail git send-email \
+		--from="Example <nobody@example.com>" \
+		--to=nobody@example.com \
+		--smtp-server="$(pwd)/fake.sendmail" \
+		--validate \
+		longline.patch 2>actual &&
+	test_path_is_file my-hooks.ran &&
+	cat >expect <<-EOF &&
+	fatal: longline.patch: rejected by sendemail-validate hook
+	fatal: command '"'"'git hook run --ignore-missing sendemail-validate -- <patch>'"'"' died with exit code 1
+	warning: no patches were sent
+	EOF
+	test_cmp expect actual
+'
+
 for enc in 7bit 8bit quoted-printable base64
 do
 	test_expect_success $PREREQ "--transfer-encoding=$enc produces correct header" '
