Sendgrid Not Working In Google App Engine Endpoints

I need to send info to the google endpoint, which then sets up object with Sendgrid and then sends the email. The emails are not working, nothing is sent through from the app engin

Solution 1:

The problem was that when creating an Sendgrid object I used username and password. When I changed that to the key generated on sendgrid it worked!!!

 SendGrid sendgrid = new SendGrid("key");