diff --git a/wp-includes/rest-api.php b/wp-includes/rest-api.php
index 8642460dd8..d59f570c02 100644
--- a/wp-includes/rest-api.php
+++ b/wp-includes/rest-api.php
@@ -1036,7 +1036,11 @@ function rest_validate_value_from_schema( $value, $args, $param = '' ) {
 				break;
 
 			case 'email' :
-				if ( ! is_email( $value ) ) {
+				// is_email() checks for 3 characters (a@b), but
+				// wp_handle_comment_submission() requires 6 characters (a@b.co)
+				//
+				// https://core.trac.wordpress.org/ticket/38506
+				if ( ! is_email( $value ) || strlen( $value ) < 6 ) {
 					return new WP_Error( 'rest_invalid_email', __( 'The email address you provided is invalid.' ) );
 				}
 				break;
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 43e8292d0d..040b966d1c 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.7-beta2-39157';
+$wp_version = '4.7-beta2-39158';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.