diff --git a/src/Object/Email.php b/src/Object/Email.php
index 28d46f50a..57eb0c17e 100644
--- a/src/Object/Email.php
+++ b/src/Object/Email.php
@@ -135,14 +135,15 @@ class Email implements IEmail
 		$headerString = '';
 
 		foreach ($this->additionalMailHeader as $name => $values) {
-			if (is_array($values)) {
-				foreach ($values as $value) {
-					$headerString .= "$name: $value\n";
-				}
-			} else {
-				$headerString .= "$name: $values\n";
+			if (!is_array($values)) {
+				$values = [$values];
+			}
+
+			foreach ($values as $value) {
+				$headerString .= "$name: $value\r\n";
 			}
 		}
+
 		return $headerString;
 	}
 
diff --git a/src/Util/Emailer.php b/src/Util/Emailer.php
index d04569823..81a2ac268 100644
--- a/src/Util/Emailer.php
+++ b/src/Util/Emailer.php
@@ -163,9 +163,9 @@ class Emailer
 
 		// generate a multipart/alternative message header
 		$messageHeader = $email->getAdditionalMailHeaderString() .
-		                 "From: $fromName <{$fromAddress}>\n" .
-		                 "Reply-To: $fromName <{$replyTo}>\n" .
-		                 "MIME-Version: 1.0\n" .
+		                 "From: $fromName <{$fromAddress}>\r\n" .
+		                 "Reply-To: $fromName <{$replyTo}>\r\n" .
+		                 "MIME-Version: 1.0\r\n" .
 		                 "Content-Type: multipart/alternative; boundary=\"{$mimeBoundary}\"";
 
 		// assemble the final multipart message body with the text and html types included