diff --git a/lib/Db/LocalMessage.php b/lib/Db/LocalMessage.php
index 7cdc984874..34fe9aa5fe 100644
--- a/lib/Db/LocalMessage.php
+++ b/lib/Db/LocalMessage.php
@@ -30,7 +30,7 @@
  * @method string getBodyHtml()
  * @method void setBodyHtml(?string $bodyHtml)
  * @method string|null getEditorBody()
- * @method void setEditorBody(string $body)
+ * @method void setEditorBody(?string $body)
  * @method bool isHtml()
  * @method void setHtml(bool $html)
  * @method bool|null isFailed()
diff --git a/lib/Service/MimeMessage.php b/lib/Service/MimeMessage.php
index 049c91f4ce..1a6dfdffa1 100644
--- a/lib/Service/MimeMessage.php
+++ b/lib/Service/MimeMessage.php
@@ -123,6 +123,8 @@ public function buildMessagePart(?string $contentPlain, ?string $contentHtml): H
 			$messagePart = $htmlPart;
 		} elseif (isset($plainPart)) {
 			$messagePart = $plainPart;
+		} else {
+			$messagePart = new Horde_Mime_Part();
 		}
 
 		if (isset($embeddedParts) && count($embeddedParts) > 0) {