Normally I've got the mandatory "Having trouble viewing this e-mail" yada yada as the very first thing in my templates. This means that whenever the e-mail is shown in a list like Gmail this is the text the reader gets.
Has anyone thought of a clever workaround? I'd like to show some relevant text as the excerpt.
It's good to think of the bigger picture, as lots of companies overlook this and is useful for other clients like Outlook.
The 'preview' text should re-enforce the key message of your email and often only requires only recycling copy from your body. Keep it short and sweet and add the standard 'view online' copy straight after.
You could definitely start with a short "In this issue: topic, topic, topic" right up front, and then get into the web version. Still easy to find and maybe even more useful as they'll know what they are going to click through for.