I remember way back in the early days of the web, around the time of Netscape 2 and backgrounds, graphic designers started to get in on the website act (I was one of them). Being graphic designers they wanted everything to look exactly the way they saw it on their machine. So rather than designing for variable width screens they added a line at the top of the site with the instruction ‘adjust your browser width to this line’. That was before anyone had invented usability. I always thought that you should be able to design for a range of devices, not just the one you were using.
Mobile email sometimes feels a bit like those early days of the web. Many brands work for 600 pixels screen – at least double the width of a mobile device. They work around it with the ‘BlackBerry users click here’ or something like that. Why can’t brand emails be designed for all devices? There’s a useful blog here about some nuts and bolts of designing mobile email. Given that up to 1/3rd of email users are accessing through their phones, it doesn’t make sense not to do it.