A pillar of content and copywriting is to write as if you’re speaking to one single person at a time. This isn’t feasible with mass email marketing, but segmenting your list and messages helps attain the same sort of feeling. Email marketing segmentation transforms generic email into personalized and tailored messages more likely to resonate with your recipients.
Well, charity: water took an alternate route. Once someone donates to a charity: water project, her money takes a long journey. Most charities don't tell you about that journey at all -- charity: water uses automated emails to show donors how their money is making an impact over time. With the project timeline and accompanying table, you don't even really need to read the email -- you know immediately where you are in the whole process so you can move onto other things in your inbox.
Mailing lists preceded web forums and can provide similar functionalities. When used in that fashion, mailing lists are sometimes known as discussion lists or discussion forums. Discussion lists provide some advantages over typical web forums, so they are still used in various projects, notably Git and Debian. The advantages over web forums include the ability to work offline, the ability to sign/encrypt posts via GPG, and the ability to use an e-mail client's features, such as filters.
People who subscribe to your list are so interested in what you have to say that they’re willing to invite you into their inbox. This is a privilege. Honor it by letting them be the first to know about new products and sales. Or, go one step further like the company Oui Shave that asks its best customers to participate in product surveys and rewards them by making them beta testers for new products.
I haven’t heard of Feedblitz – just looking at their website now. Appears that they’re a Feedburner replacement specialising in RSS-to-email (sending your blog subscribers an email about latest posts). Their pricing looks a bit steep (considering Feedburner was free) – so I’d probably choose Mailchimp or Aweber over them? That way you can message up to a few thousand people free of charge.