diff --git a/snappymail/v/0.0.0/app/libraries/MailSo/Base/Http.php b/snappymail/v/0.0.0/app/libraries/MailSo/Base/Http.php
index 280563d2a..ab92cdabe 100644
--- a/snappymail/v/0.0.0/app/libraries/MailSo/Base/Http.php
+++ b/snappymail/v/0.0.0/app/libraries/MailSo/Base/Http.php
@@ -431,14 +431,14 @@ class Http
 			{
 				if ($bSetCacheHeader)
 				{
-					\header('Cache-Control: public', true);
-					\header('Pragma: public', true);
-					\header('Last-Modified: '.\gmdate('D, d M Y H:i:s', $iUtcTimeStamp - $iExpireTime).' UTC', true);
-					\header('Expires: '.\gmdate('D, j M Y H:i:s', $iUtcTimeStamp + $iExpireTime).' UTC', true);
+					\header('Cache-Control: public');
+					\header('Pragma: public');
+					\header('Last-Modified: '.\gmdate('D, d M Y H:i:s', $iUtcTimeStamp - $iExpireTime).' UTC');
+					\header('Expires: '.\gmdate('D, j M Y H:i:s', $iUtcTimeStamp + $iExpireTime).' UTC');
 
 					if (0 < strlen($sEtag))
 					{
-						\header('Etag: '.$sEtag, true);
+						\header('Etag: '.$sEtag);
 					}
 				}
 			}
@@ -463,8 +463,7 @@ class Http
 			$bCache = true;
 			\header('Expires: Mon, 26 Jul 1997 05:00:00 GMT');
 			\header('Last-Modified: '.\gmdate('D, d M Y H:i:s').' GMT');
-			\header('Cache-Control: no-store, no-cache, must-revalidate, max-age=0');
-			\header('Cache-Control: post-check=0, pre-check=0', false);
+			\header('Cache-Control: no-store, no-cache, must-revalidate, max-age=0, post-check=0, pre-check=0');
 			\header('Pragma: no-cache');
 		}
 	}
@@ -478,10 +477,10 @@ class Http
 		if (false === $bCache)
 		{
 			$bCache = true;
-			\header('Cache-Control: private', true);
-			\header('ETag: '.$sEtag, true);
-			\header('Last-Modified: '.\gmdate('D, d M Y H:i:s', $iLastModified).' UTC', true);
-			\header('Expires: '.\gmdate('D, j M Y H:i:s', $iExpires).' UTC', true);
+			\header('Cache-Control: private');
+			\header('ETag: '.$sEtag);
+			\header('Last-Modified: '.\gmdate('D, d M Y H:i:s', $iLastModified).' UTC');
+			\header('Expires: '.\gmdate('D, j M Y H:i:s', $iExpires).' UTC');
 		}
 	}
 
diff --git a/snappymail/v/0.0.0/app/libraries/RainLoop/Actions/Contacts.php b/snappymail/v/0.0.0/app/libraries/RainLoop/Actions/Contacts.php
index 727a55c38..20865b619 100644
--- a/snappymail/v/0.0.0/app/libraries/RainLoop/Actions/Contacts.php
+++ b/snappymail/v/0.0.0/app/libraries/RainLoop/Actions/Contacts.php
@@ -264,8 +264,8 @@ trait Contacts
 		$oAccount = $this->getAccountFromToken();
 
 		\header('Content-Type: text/x-vcard; charset=UTF-8');
-		\header('Content-Disposition: attachment; filename="contacts.vcf"', true);
-		\header('Accept-Ranges: none', true);
+		\header('Content-Disposition: attachment; filename="contacts.vcf"');
+		\header('Accept-Ranges: none');
 		\header('Content-Transfer-Encoding: binary');
 
 		$this->oHttp->ServerNoCache();
@@ -279,8 +279,8 @@ trait Contacts
 		$oAccount = $this->getAccountFromToken();
 
 		\header('Content-Type: text/csv; charset=UTF-8');
-		\header('Content-Disposition: attachment; filename="contacts.csv"', true);
-		\header('Accept-Ranges: none', true);
+		\header('Content-Disposition: attachment; filename="contacts.csv"');
+		\header('Accept-Ranges: none');
 		\header('Content-Transfer-Encoding: binary');
 
 		$this->oHttp->ServerNoCache();
diff --git a/snappymail/v/0.0.0/app/libraries/RainLoop/Actions/Raw.php b/snappymail/v/0.0.0/app/libraries/RainLoop/Actions/Raw.php
index 6a2b7ccdb..18ed472dc 100644
--- a/snappymail/v/0.0.0/app/libraries/RainLoop/Actions/Raw.php
+++ b/snappymail/v/0.0.0/app/libraries/RainLoop/Actions/Raw.php
@@ -18,7 +18,7 @@ trait Raw
 		$iUid = (int) (isset($aValues['Uid']) ? $aValues['Uid'] : 0);
 		$sMimeIndex = (string) (isset($aValues['MimeIndex']) ? $aValues['MimeIndex'] : '');
 
-		\header('Content-Type: text/plain', true);
+		\header('Content-Type: text/plain');
 
 		return $this->MailClient()->MessageMimeStream(function ($rResource) {
 			if (\is_resource($rResource))
@@ -157,9 +157,9 @@ trait Raw
 			{
 				\header('Content-Type: '.$sContentTypeOut);
 				\header('Content-Disposition: attachment; '.
-					\trim(\MailSo\Base\Utils::EncodeHeaderUtf8AttributeValue('filename', $sFileNameOut)), true);
+					\trim(\MailSo\Base\Utils::EncodeHeaderUtf8AttributeValue('filename', $sFileNameOut)));
 
-				\header('Accept-Ranges: none', true);
+				\header('Accept-Ranges: none');
 				\header('Content-Transfer-Encoding: binary');
 
 				\MailSo\Base\Utils::FpassthruWithTimeLimitReset($rResource);
@@ -217,7 +217,7 @@ trait Raw
 							{
 								$oImage = static::loadImage(\stream_get_contents($rResource), $bDetectImageOrientation, 60);
 								\header('Content-Disposition: inline; '.
-									\trim(\MailSo\Base\Utils::EncodeHeaderUtf8AttributeValue('filename', $sFileNameOut.'_thumb60x60.png')), true);
+									\trim(\MailSo\Base\Utils::EncodeHeaderUtf8AttributeValue('filename', $sFileNameOut.'_thumb60x60.png')));
 								$oImage->show('png');
 //								$oImage->show('webp'); // Little Britain: "Safari says NO"
 								exit;
@@ -235,7 +235,7 @@ trait Raw
 								$sLoadedData = \stream_get_contents($rResource);
 								$oImage = static::loadImage($sLoadedData, $bDetectImageOrientation);
 								\header('Content-Disposition: inline; '.
-									\trim(\MailSo\Base\Utils::EncodeHeaderUtf8AttributeValue('filename', $sFileNameOut)), true);
+									\trim(\MailSo\Base\Utils::EncodeHeaderUtf8AttributeValue('filename', $sFileNameOut)));
 								$oImage->show();
 							}
 							catch (\Throwable $oException)
@@ -254,7 +254,7 @@ trait Raw
 						if (!headers_sent()) {
 							\header('Content-Type: '.$sContentTypeOut);
 							\header('Content-Disposition: '.($bDownload ? 'attachment' : 'inline').'; '.
-							\trim(\MailSo\Base\Utils::EncodeHeaderUtf8AttributeValue('filename', $sFileNameOut)), true);
+								\trim(\MailSo\Base\Utils::EncodeHeaderUtf8AttributeValue('filename', $sFileNameOut)));
 
 							\header('Accept-Ranges: bytes');
 							\header('Content-Transfer-Encoding: binary');
@@ -298,7 +298,7 @@ trait Raw
 
 								if (0 < $iContentLength)
 								{
-									\header('Content-Length: '.$iContentLength, true);
+									\header('Content-Length: '.$iContentLength);
 									\header('Content-Range: bytes '.$sRangeStart.'-'.(0 < $iRangeEnd ? $iRangeEnd : $iFullContentLength - 1).'/'.$iFullContentLength);
 								}
 
diff --git a/snappymail/v/0.0.0/app/libraries/RainLoop/Service.php b/snappymail/v/0.0.0/app/libraries/RainLoop/Service.php
index e77b55020..ec04ffeae 100644
--- a/snappymail/v/0.0.0/app/libraries/RainLoop/Service.php
+++ b/snappymail/v/0.0.0/app/libraries/RainLoop/Service.php
@@ -53,7 +53,7 @@ class Service
 		$sServer = \trim($this->oActions->Config()->Get('security', 'custom_server_signature', ''));
 		if (0 < \strlen($sServer))
 		{
-			\header('Server: '.$sServer, true);
+			\header('Server: '.$sServer);
 		}
 
 		\header('Referrer-Policy: no-referrer');
@@ -65,14 +65,14 @@ class Service
 		$this->setCSP();
 
 		$sXFrameOptionsHeader = \trim($this->oActions->Config()->Get('security', 'x_frame_options_header', '')) ?: 'DENY';
-		\header('X-Frame-Options: '.$sXFrameOptionsHeader, true);
+		\header('X-Frame-Options: '.$sXFrameOptionsHeader);
 
 		$sXssProtectionOptionsHeader = \trim($this->oActions->Config()->Get('security', 'x_xss_protection_header', '')) ?: '1; mode=block';
-		\header('X-XSS-Protection: '.$sXssProtectionOptionsHeader, true);
+		\header('X-XSS-Protection: '.$sXssProtectionOptionsHeader);
 
 		if ($this->oActions->Config()->Get('labs', 'force_https', false) && !$this->oHttp->IsSecure())
 		{
-			\header('Location: https://'.$this->oHttp->GetHost(false, false).$this->oHttp->GetUrl(), true);
+			\header('Location: https://'.$this->oHttp->GetHost(false, false).$this->oHttp->GetUrl());
 			exit(0);
 		}
 
@@ -224,7 +224,7 @@ class Service
 			// Knockout.js requires eval() for observable binding purposes
 			//$sContentSecurityPolicy = \preg_replace("/(script-src[^;]+)'unsafe-eval'/", '$1', $sContentSecurityPolicy);
 		}
-		\header('Content-Security-Policy: '.$sContentSecurityPolicy, true);
+		\header('Content-Security-Policy: '.$sContentSecurityPolicy);
 	}
 
 	private function staticPath(string $sPath) : string
diff --git a/snappymail/v/0.0.0/app/libraries/RainLoop/ServiceActions.php b/snappymail/v/0.0.0/app/libraries/RainLoop/ServiceActions.php
index d644bccf4..a72d72dbe 100644
--- a/snappymail/v/0.0.0/app/libraries/RainLoop/ServiceActions.php
+++ b/snappymail/v/0.0.0/app/libraries/RainLoop/ServiceActions.php
@@ -393,8 +393,8 @@ class ServiceActions
 				$sMethodName = 'Raw'.$sAction;
 				if (\method_exists($this->oActions, $sMethodName))
 				{
-					\header('X-Raw-Action: '.$sMethodName, true);
-					\header('Content-Security-Policy: script-src \'none\'; child-src \'none\'', true);
+					\header('X-Raw-Action: '.$sMethodName);
+					\header('Content-Security-Policy: script-src \'none\'; child-src \'none\'');
 
 					$sRawError = '';
 					$this->oActions->SetActionParams(array(