Working on a new article on Adviso blog (scheduled for Thursday), I have just found this very useful online tool: Email on Acid allows you to test a newsletter in 9 most used webmails, including Windows Live, Outlook and Yahoo Mail. It is free, you only have to register to be able to run a test. The test requires either the URL of the email or its HTML code (which basically means we could test other companies newsletters too, which of course I did). Coming soon on Adviso: the answer to the famous question « How wide should my email be? »

The only limit I can see is that internauts can modify the width of their webmails columns (meaning the width of the content column can vary) on most webmails. I have just sent Email on Acid an email, asking how reliable the tests are speaking about width in pixels. They confirmed that the window of their test is set to be 100% of the screen width (meaning around 992 pixels with 1 024*768 resolution), wich is a good representation of the actual size of the webmail window. Of course, there is still the fact that internauts modify their webmail layout. But though, it’s still impossible to test this (unless you use surveys, of course)!