MailChimp 'opened' stats and MS Outlook reading pane

I'd said in a previous post about MailChimp reports that I was a bit disappointed with a 25% open rate from our mailing list emails. However, Marta suspected that this was partly due to high numbers of users subscribing via their official University of Leicester email account which, common to many institutions, uses Microsoft Outlook. And the default setting for Outlook is for the reading pane to be on. This enables users to read an email without actually clicking on it to open it. Well, Marta and I tested it, and she was indeed correct - viewing a MailChimp email via the Outlook reading pane isn't recorded as an open in MailChimp reports. And given that more than 75% of our (now 4,000 strong) list use their .le.ac.uk address - I've come to the happy conclusion that our open rate is much better than I thought :)