Include 3 to 6 proposals with your note, listing the title and a 25-word synopsis for each. Follow the proposals with a writing sample. Choose or produce a writing sample that bears on the topic or theme of the e-Zine, and have it be about the same length as the article will be. Unless otherwise specified, the proposals and writing sample should be in the body of your e-mail message rather than in an attachment. Don't use tabs to separate paragraphs, use blank lines.
Tabs are more difficult to reproduce for a web page.
If the editor accepts some of your proposals, it's time to get to work. Internet articles need to be as well-researched as print articles, and just as well written. Make an outline for yourself and follow it. The Internet is a unique medium, in that any references you make can be chased down. Wherever possible, when you mention a resource, a statistic or a lead, link it in your article.