Feedburner has an awesome tool for creating a subscription list that sends RSS email updates from your site to users inboxs, and it's free!

Users only receive email when your rss feed is updated with new content.

Features;

• choose which email address your newsletter will be sent from
• add your logo to the email (must be no larger then 200x200 pixels
• customize your welcome message
• customize the way your newsletter is displayed including colors and font.
• select which language you want to use for your subscriber box including English, Spanish, French, German, Portuguese and Japanese.

You can also choose the subject title of your email. You can use your blog title or company name. Alternatively you can insert your posts title in to the subject line using

${LatestItemTitle}

Feedburner allows you to choose a time zone for your email delivery and select what time you'd like your customers to receive it.

Monetize If you use adsense, you can also set your newsletter feed to include ads in the email.

Subscribe to WebGeek.Me for an example of how feedburner newsletters appear in your inbox and updates on the site!