Here’s a useful bit of research, from Displaying and optimising ALT text in popular email clients on the Campaign Monitor blog. If you send out emails with images in them, even if they’re only mastheads or company logos (like this blog’s email edition), then it’s a fact of life that some of your readers won’t see those images, either because they’ve chosen to block them, or the Network Nazis at their company have decided for them …or they may have them “off” by default, but available if they specifically select to view them individually.
For those people, you need to have an “alt tag” associated with every image, so a label appears in its place. That way they get to see what they’re missing, and it’s another opportunity to state your sales message or slogan. Microsoft’s Outlook application, in its various guises, is the most widely-used email client, and this does respect and display alt tags, although prefaced by an irritating warning in most versions. If you’re feeling really ambitious, the article points out that you can style the “alt” text in size and colour too.
PS: A couple of people who planned to attend our free Google AdWords seminar/workshop next week are now unable to make it, so we have a few spaces. This free event will be really useful if you’re getting into AdWords, or think your company really ought to be there. The feedback from the marketing managers who attended our last event was really gratifying. If you’d like to attend, the details are here.