If you're looking for a newsletter system that works well with Notion, Notocat is a great choice. It lets you create, manage and send newsletters right in Notion, with features like customizable templates, multimedia support and scheduled sending. Notocat also tracks opens and clicks, offers custom signup forms and supports custom domains with DKIM and Return-Path for better deliverability. The service offers a free trial and flexible pricing options, so it should be adaptable to your needs and budget.
Another option is Bloom, an AI-powered service that can help you automate and personalize newsletter content. Bloom uses sophisticated AI technology to help you quickly create and style content for specific audience segments. It can draw data from documents, websites and social media to target your newsletters, for example if you're a real estate agent or small business owner. Bloom charges for its services on a subscription basis, but it can help you automate and improve your email marketing.