We web designers and developers can easily forget how much of our day to day language is incomprehensible to outsiders who don't know their AJAX from their Jif. Over time, we tend to develop ways of talking to our clients that they can actually understand, which is great.
However, there are other areas where industry specific jargon can creep in without being noticed. One such spot is in our MailBuild templates. Not so much in the technical construction of the templates, which are intended for clients, but more in the labelling used, which is aimed at your client's subscribers.
For example: You know what a web version is, and your client might know, but their readers? Probably not. Instead of using the actual phase web version in your template, why not describe what it actually is. "If you can't read this email, view it on the web".