Most email clients, both online and offline, block images by default. The age old practise of web accessibility becomes ever more important in instances such as HTML email design.
Usage of ALT tags should be mandatory. But I don't just mean putting in ALT tags just to explain what's behind the image. Go one up and get your recipients to download the images and entice them to update their preferences in their email client so that future images from your campaign will be automatically downloaded. Gmail offers a similar function:
Now here's a clever little idea you could use for your client's next campaign. This works especially well for email campaign designs that are predominantly image based.
My client was an up-scale restaurant, catering to the hip and trendy crowd who're looking for great dining at reasonable prices, and a casual, comfortable atmosphere. Bearing the more casual target in mind, I took a little different approach to the ALT tag:
And here's the actual email campaign the way it was meant to be, with images downloaded:
The click-open rate increased on this campaign by almost 35% from the previous campaign. Though I cannot attribute it solely to my tweak on the ALT tag, I'm certain that it definitely helped somewhat.
Go on and get your client's approval to have fun with the ALT tags for their next campaign. Monitor your reports to see what works and what doesn't. But most importantly, get creative! By putting a teaser behind the images in the ALT tags, you engage and intrigue your recipients on a whole different level.

A great creative idea, and one to help induce clicks in the face of image-blocking set to 'on' by default... but really, should the use of image-only email campaigns be encouraged to clients at all, when they should be using HTML text blocks to get the core message across without having to worry about image blocking?
http://www.carbongraffiti.com/2008/06/11/image-only-images-lose-you-money/
Cheers,
J
Posted by: Jon Aizlewood | July 15, 2008 at 04:35 PM