I heard about this product from ex-co-worker, Lance Leonard. If you are looking to do an e-mail newsletter for your business you should check it out. If you want to add an e-mail newsletter to supplement your blog, it's probably overkill.
Campaign Monitor is an email newsletter and list management tool built for web designers who can design great looking emails, but need software to send their campaign, track the results and manage their subscribers.
Pricing is $5 + 1 cent / recipient for each campaign. It's free for 5 or less recipients which makes it a good way to check out their service.
Is that Brent Spiner's brother on their home page? :)