Email Image Alt text – size does matter

[tweetmeme source= “getintheinbox” only_single=false]
On reading Campaign Monitor’s recent ALT text review by Ros Hodgekiss (05/10/2010), we find, amongst many other cool things, that the length of the alt text can decide whether or not the alt text is displayed at all in Windows Live Mail, Yahoo Mail, the iPhone, Gmail and Apple Mail.
(Although the CM article also states in another table that Windows Live Mail doesn’t render alt text at all?)

Apparently if your alt text will actually extend it longer than the width of the image, it will not be rendered.

So the short solution is to keep it short.

I find my self asking why?

Back in 2009 I wrote Spammer vs the Spam Filter, for Pure360, explaining the evolutionary path of spam filters and image blocking. One statement I made was that the filter  – most commonly Spam Assassin – tests your image to text ratio. It will calculate the total image coverage with a bit of maths on the dimensions of all of the images in your html version and then count all of the visible characters, presume or pretend that they are 12px each and then calculate the total coverage. It will then compare the two and if it is any more than 60 / 40 text to image, you are likely to get a warning of some sorts.

Since then I have found that when you get a warning, by adding a bag load more alt text you can lower the score, but you cannot remove it completely. One gestimation could be that alt text chars count as 6px for instance.

One could say that if you need to add more alt text to fix your spam warnings you are obviously doing something wrong – I won’t disagree with that but some brands have very complex and ignorant decision making process which means that the execs are forced to send image heavy emails, so this can help.

Also the alt text should be a description of the image, according to W3C, so it supports screen readers. I say that the rules are slightly different for emails and you can be a bit more flexible in getting the message across while the images are blocked and for screen readers. For instance the image button could be the call to action text and not describe the image. A spacer image should not need any alt text at all.

Now these new discoveries from CM mean that we have far less to play with in our emails’ alt text and those people who are used to packing the alt text in, no longer have that luxury – although I suspect that people who are adamant about giant images don’t care about the alt text any way.

So you could say that some inboxes are doing it for the same reasons that they hid images in the first place and to give the good marketers even more opportunity to separate themselves from the spammers. Or it cold have been a UI decision with everything trying to be better for smart phones – so rendering long alt text would be a bad user experience and having two rendering engines for desktop and mobile was not worth the effort…This adds another feature request to go the Email Standards test.

According to CM: Yahoo Mail, iPhone, Gmail, Apple Mail & Thunderbird will all allow you to style the alt text using in-line CSS with a style attribute to the <img> tag.

I’d be interested to see is if styling the alt text to make the chars smaller, lets you get more in or not?