diff --git a/wp-includes/version.php b/wp-includes/version.php
index 6f11498f42..247e8e266e 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.4.1-alpha-47579';
+$wp_version = '5.4.1-alpha-47581';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.
diff --git a/wp-mail.php b/wp-mail.php
index 02635157c5..1d5fbedf03 100644
--- a/wp-mail.php
+++ b/wp-mail.php
@@ -213,7 +213,7 @@ for ( $i = 1; $i <= $count; $i++ ) {
 
 	$post_title = xmlrpc_getposttitle( $content );
 
-	if ( '' === $post_title ) {
+	if ( '' === trim( $post_title ) ) {
 		$post_title = $subject;
 	}