1. Go to evenium.com 
  2. Click My Events 
  3. Click on the name of the event under the I organize section
  4. Click Configuration on the purple bar 
  5. Click Invitations & Emails 
  6. Click See all emails sent
  7. Click on the Errors column header
  8. If you have a sent email that has errors associated to it, click on the name of the email under the Message title column
  9. Filter the Status column on the Error value.