This formal event invitation email sample has three great elements: 1) targeted content, 2) a strong CTA, and 3) social proof. The best-use case for such event invites is business communication. While Buffer targeted people who were interested in the product, it was a great idea to provide a clear value proposition in the "What you'll learn" section as well as a client testimonial. It can be a thank-you email or a thank-you phone call—the important part is the thanks. 8. Stay in touch. Now that you have some donors, keep the relationships going and the donations coming. Follow up by updating them on your nonprofit's work, offering other ways to get involved, and, of course, saying thank you a few more times.