This is very nice. I am interested in whether or not an open source library was used for much of the processing, or if it was written from scratch entirely.

If there is no open source library available to convert stylesheets+HTML to inline CSS, it would be a good idea to consider open sourcing some of the code behind this app.

Either way, very nice app - great job!

Rails library for inlining css:

http://github.com/milk1000cc/docomo_css/

Actually this is a python project using CSSUtils and lXML

This is going to be a huge help in the day job - thanks.

Here is a related article I’ve found useful recently: http://www.campaignmonitor.com/css/

I always use this one: http://code.dunae.ca/premailer.web/

"Premailer is written in Ruby, with a lot of help from Hpricot"

Cool, but might I ask, why would I need this? If an email client can deal with html, can't it deal with CSS as well?

You can support CSS and not the <style> tag. This tool converts a stylesheet to inline styles for you. One great example for usage is in an eBay auction.

Email clients are known for handling HTML in a variety of broken ways, one worse than the other. From what I remember Notes is the worst one to handle, followed by Outlook. Since a few people use those clients, writing stuff they can display is required.

A funny thing I've read is that Outlook 2007 is apparently worse than the 2003 version. See e.g. http://www.google.se/search?q=outlook+html+rendering

It seems to do what it advertises well, but it's still not very useful in real life: it doesn't warn when you use poorly supported styles, e.g. background-image isn't supported in Outlook 2007.

This is awesome. I occasionally do email mailouts for an old friend and its normally pretty manual. I was thinking about getting around to building something like this, but this works perfectly!