diff --git a/Classes/Service/MailTemplateService.php b/Classes/Service/MailTemplateService.php
index 5d07f0704d7eaad7e18fba8918ed10955cac6ebf..37b6c6f23b386996ec1425c82f4cede666f5997d 100644
--- a/Classes/Service/MailTemplateService.php
+++ b/Classes/Service/MailTemplateService.php
@@ -949,16 +949,18 @@ class MailTemplateService {
 	 * @param array $markers
 	 * @return string
 	 */
-	private function getAllMarker(array $markers) {
+	private function getAllMarker(array $markers): string {
 		$allMarker = '';
 
 		foreach ($markers as $key => $value) {
-			if (!\is_array($value)) {
-				$allMarker .= $value . PHP_EOL;
-			} else {
+			if (\is_string($value)) {
+				$allMarker .= $key  . ': ' . $value . PHP_EOL;
+			} elseif (\is_array($value)) {
 				foreach ($value as $innerKey => $innerValue) {
-					$allMarker .= $innerValue . PHP_EOL;
+					$allMarker .= $key  . ': ' . $innerValue . PHP_EOL;
 				}
+			} elseif (\is_bool($value)) {
+				$allMarker .= $key  . ': ' . $value . PHP_EOL;
 			}
 		}