Here's a list of blogs that cover email marketing, deliverability, phishing, spam, and just email in general:

• ActivSoftware Email Blog - this one.
• eROI Blog - Email Marketing News and Strategies
• No Man is an Iland - Email marketing news, advice and best practices
• The Quiet Revolution - Email marketing
• eINFO - articles and case studies about email marketing
• OnlyOnce - A first-time CEO writes about email and entrepreneurship
• Not That you asked
• Chip's Tips - Email Deliverability
• The email wars - Email Marketing News, Email Marketing Case Studies, Email Marketing Delivery, The Email Wars, eROI

If you know of any other blogs that are about email please post a comment.