If when looking at the Alert Summary report all of your e-mail sends to representatives are failing. 
  1. Go to the alert and edit it.
  2. Go to Step 4. Select Targets
  3. Click on the link for ""Review Legislator Contact Status"
  4. Now click on "Click here to view the individual Legislator Contactability Index"
  5. Now choose where the official is from, and make sure the via E-Mail column has "Yes" if it has "No" that is why all the emails are failing.