It’s relatively common knowledge that some email clients block images in emails by default. But just which ones block images and to what extent? This is a common question, and the answer is expectedly complicated. I will attempt to clear up the confusion and then offer some tips to best design your emails to work regardless of image blocking. But first, the rundown of major clients and their peculiarities:
As you can see from these tables, image rendering is very inconsistent across clients, but the biggest trend, especially in the more recent clients, is that images are usually blocked by default. Therefore, here are some tips to improve your email designs with blocked images taken into account:
- Ask your subscribers to add your from address to their address book or "Safe Senders" list.
- Include a text-based "view as a webpage" link at the top of the email.
- Important content such as headlines, calls to action, and other links should be text, not images, when possible.
- In general, use as few images as possible and as much text as possible.
- Include height and width properties in the image tag to ensure that the image placeholder doesn’t change your layout.
- Always use relevant and styled ALT text for all images (see our previous blog post on this topic for more useful information).
- Test, test, TEST! Use Web Developer Toolbar for Firefox or Internet Explorer Developer Toolbar for IE to see your email layout with images turned off before you send. Also, see our previous blog post for more information on using the Web Developer Toolbar for Firefox.
Additional email clients that are known to block images by default include:
Android Gmail, AOL 9, AT&T, BT, Comcast, Cox, Earthlink, Mac.com, Netzero/Juno, Outlook Express, RoadRunner, Sina, Sohu, Telefonica, Thunderbird, Tiscali, Verizon, Virgilio, Windows Mobile 6, and Ya.com.
ExactTarget Campaign Solutions Team