In the latest MarketingSherpa Email Marketing Benchmark Report (2010), a survey of email recipients found that only 33% have images turned on by default. That means that 67% – or two-thirds of recipients – don’t.
Many popular email clients and webmail providers block images in emails by default for unknown senders, including Outlook 2007 & 2010, Gmail, Yahoo and Hotmail. When emails arrive in a recipient’s inbox with images disabled, they will be presented with an alert which gives them the option to ‘click to download images’ which will activate images for that particular email only. Most clients also have an option to ‘Always display images for this sender’ but how this works varies based on the software and version.
In Outlook 2007 for example, the image download settings are managed in the Trust Centre. Based on the settings in here, Outlook will automatically display images for email senders which have been previously added to the safe list (this may happen if an email is filtered to the junk mail folder then marked as ‘not spam’) or from senders which appear in a users address book.
If image blocking is enabled in Outlook, there is no way for an email sender to over-ride these settings. The first instance of any HTML email from a new sender will have images blocked by default until the user vouches for the sender by either adding them to their safe list or address book.
There are some certification services which will enable default image downloading in certain webmail clients however this can be a costly exercise and there’s no guarantees. Instead I would recommend following these steps to minimise the impact of image blocking:
- Make sure there is HTML text and key messages visible in the preview pane, avoid relying on images too heavily and don’t use images for call to actions.
- Use the pre-header of the welcome email to encourage recipients to ‘add to safe sender’. Some people link to a landing page which provides an explanation on how to do this in different email clients e.g.
- Use the pre-header to convey the campaign value proposition which encourages recipients to download images
UPDATE 18/08/2011: How to get around disabled images (2010 article)
Preview Panes, Image Blocking