diff --git a/README.md b/README.md
index 0b417650..64d1289f 100644
--- a/README.md
+++ b/README.md
@@ -399,6 +399,7 @@ Table of Contents
   * [testmail.app](https://testmail.app/) - Automate end-to-end email tests with unlimited mailboxes and a GraphQL API. 100 emails/month free forever, unlimited free for open source.
   * [trashmail.com](https://www.trashmail.com) - Free disposable email addresses with forwarding and automatic address expiration
   * [Sender](https://www.sender.net) Up to 15 000 emails/month - Up to 2 500 subscribers
+  * [Buttondown](https://buttondown.email/) — Newsletter service. Up to 1,000 subscribers free
 
 ## CDN and Protection