These e-mail services are featured in detail at our January 2011 CUG meeting.
Premailer has been replaced by the our own CSS Inlner Tool within the HTML editor on this site.
You can access the tool by going to the HTML editor here: https://convio.berkeley.edu/content/html-e-mail-editor-tool
Documentation can be accessed here:
Email on Acid is a paid on-line e-mail client testing service which can help you tremendously with improving the quality of your designs.
By providing an interface to view what your e-mail will look like in nearly every major e-mail client, you can see where your design may fail before it's sent out.
Email on Acid provides lots of tools for helping decode problems with your code as you work.
You can test-drive this tool by using their free, limited tool.
They also have a fantastically useful (required reading!) blog: