As many as 19% of email recipients will not open an email that hasn't rendered properly, as they assume it is spam. So it's critical for email marketers to design and code their templates to ensure they render correctly in all relevant email clients.

In our newly published 2009 Hitting the Mark benchmark survey, we used the Inbox Preview tool within dotMailer to test how consistently the email campaign templates of 43 major name retailers rendered in over 20 different email clients (for full list of email clients included in the Inbox Preview report, download the full report).

We found the results were mixed across the retailers when it came to deliverability, with an average score of 7.2 out of 12. Whilst 12% of those surveyed achieved top marks for their emails rendering correctly in all email clients tested, 10% of the retailers scored just 3 marks out of the 12 available.