Email newsletter services such as MailChimp and Campaign Monitor offer a highly effective way to send out mass emails:
- Automatically managed unsubscribes/subscribes
- Track deliveries, click-throughs, unsubscribes, forwards, etc
- Create and manage reusable email templates
- Automatic spam filter detection
- Avoid bulk-email sender warnings and bans from your ISP
If you are looking to send email newsletters, services such as these will make it a far simpler, and more enjoyable process, and the costs are low.