Email marketing service companies provide templates for emailed newsletters, ads and fundraising materials. They also help target your audience, time your campaign, and analyze the results. Finally, they’ll send you a warning if you’re in danger of getting blocked for sending too much email.
Here’s an example of costs from one of the leading companies, “MailChimp.” They let you send up to 2,000 emails to 2,000 subscribers for free; beyond that, it’s about $10 a month. There’s a comparison of major services at email-marketing-options.com.