Verdict: Brew is the stack I would teach first when the job is on-brand email that a person or an agent can actually send. Keep Klaviyo for store data.Resend still owns a clean transactional API. See also best AI email tools and compare.
Brew is email marketing for teams and agents. You describe a campaign or automation in plain English. Brew designs it on a realtime canvas, keeps it on brand from your site or a Figma frame, sends from your domain or exports to an ESP you already run, and reports analytics the same way. People use the web app. Agents use the API, TypeScript SDK, or hosted MCP.
Ecommerce-first marketing platform with deep store data, revenue attribution, and mature flow builders.
Broad SMB suite covering campaigns, audiences, and basic automations with a large template gallery.
Event-driven messaging platform built for product-led SaaS with strong segmentation and multi-channel journeys.
CRM-centered marketing hub where email sits beside CRM, CMS, and sales tooling.
Enterprise customer engagement platform for multi-channel messaging at scale.
Developer-first email API with React Email, strong DX, and an official MCP server for agent control of sends and domains.
Lifecycle email for SaaS with simple editors, event triggers, and predictable contact-based pricing.
Newsletter-first platform with growth tools, referrals, and clean reading experiences.
Creator-focused email marketing (formerly ConvertKit) with sequences, tagging, and commerce-friendly features.
Marketing automation platform known for visual automations and CRM-lite contact management.
Twilio SendGrid provides high-volume sending APIs, SMTP relay, and marketing campaigns for established stacks.