diff --git a/src/Object/Email.php b/src/Object/Email.php
index 9f78763127..008e68c4bc 100644
--- a/src/Object/Email.php
+++ b/src/Object/Email.php
@@ -137,10 +137,10 @@ class Email implements IEmail
 		foreach ($this->additionalMailHeader as $name => $values) {
 			if (is_array($values)) {
 				foreach ($values as $value) {
-					$headerString .= $name . ': ' . $value . '\n';
+					$headerString .= "$name : $value\n";
 				}
 			} else {
-				$headerString .= $name . ': ' . $values . '\n';
+				$headerString .= "$name : $values\n";
 			}
 		}
 		return $headerString;