More on best practices
Mark Brownlow took my post about best practices and expanded on the theme. He is absolutely right and I encourage everyone to go read his article.
The takeaway here is not to rush out and start ignoring best practices. Without the background understanding, that way lies email marketing hell.
But if you can gain (or hire) a more nuanced understanding of issues, you might be able to break selected rules to the benefit of both you and your subscribers.