use error object for 'err' callback param

Error object contain stacktraces and additional information that helps
debug potential issues. They are expected as the first argument versus
just a string.

1 files changed, 2 insertions, 2 deletions

diff --git a/lib/sendgrid.js b/lib/sendgrid.js
index be04e96..ebda0cd 100644
--- a/lib/sendgrid.js
+++ b/lib/sendgrid.js
@@ -67,11 +67,11 @@ module.exports = function(api_user, api_key) {
       if (json.message !== 'success') {
         var error = 'sendgrid error';
         if (json.errors) { error = json.errors.shift(); }
-        return callback(error, null);
+        return callback(new Error(error), null);
       }
 
       return callback(null, json);
-    }); 
+    });
 
     var form          = email.toWebFormat();
     form['api_user']  = api_user;