diff --git a/routes/invite.js b/routes/invite.js
index af6a6a4..f5a0250 100644
--- a/routes/invite.js
+++ b/routes/invite.js
@@ -13,13 +13,17 @@ module.exports = function (app) {
   app.post('/invites', function(req, res, next) {
 
     if(!validator.isEmail(req.body.email)) {
-      res.status(400).send('Invalid email');
+      return res.status(400).send('invalid_email');
     }
 
     function success() {
       res.status(200).end();
     }
 
+    function alreadyInvited(email) {
+      res.status(400).send('already_invited');
+    }
+
     slack
       .createInvite(req.body.email)
       .then(function() {
@@ -37,6 +41,11 @@ module.exports = function (app) {
       })
       .then(success)
       .catch(function(err) {
+
+        if(err === 'already_invited') {
+          return alreadyInvited(req.body.email);
+        }
+
         var message = 'Creating automatic invitation failed for: ' + req.body.email + ' reason: ' + err;
         slack.createMessage(message);
 
diff --git a/services/github.js b/services/github.js
index 1c7b0b9..d987abc 100644
--- a/services/github.js
+++ b/services/github.js
@@ -49,10 +49,22 @@ module.exports = {
       .query({q: email})
       .set('Authorization', 'token ' + config.github.token)
       .end(function(error, response){
-        if (error) {
-          reject(error);
+        if(error) {
+          return reject(error);
         }
-        resolve(response.body);
+
+        if(!response.body.items) {
+          return reject(new Error(response.body.message));
+        }
+
+        if(response.body.items.length === 0) {
+          return reject(new Error('Not Found'));
+        }
+
+        resolve(response.body.items[0]);
+      });
+    });
+  },
   /**
    * Invite user to organization
    */