From 43d885b922487d55036c31f2664da7598f521128 Mon Sep 17 00:00:00 2001
From: the-djmaze <>
Date: Mon, 12 Jun 2023 10:58:56 +0200
Subject: [PATCH] Nextcloud Cannot modify header information
 https://github.com/the-djmaze/snappymail/issues/929#issuecomment-1582552784

---
 snappymail/v/0.0.0/include.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/snappymail/v/0.0.0/include.php b/snappymail/v/0.0.0/include.php
index 8e4d71db0..48aff66ad 100644
--- a/snappymail/v/0.0.0/include.php
+++ b/snappymail/v/0.0.0/include.php
@@ -130,7 +130,7 @@ if (empty($_SERVER['HTTPS']) || 'off' === $_SERVER['HTTPS']) {
 if (isset($_SERVER['REQUEST_SCHEME']) && 'https' === $_SERVER['REQUEST_SCHEME']) {
 	$_SERVER['HTTPS'] = 'on';
 }
-if (isset($_SERVER['HTTPS'])) {
+if (isset($_SERVER['HTTPS']) && !headers_sent()) {
 	header('Strict-Transport-Security: max-age=31536000');
 }