Choosing an agent-ready ESP in 2026
Fatima Bello · B2B email strategist · June 14, 2026
Our growth team spent Q1 evaluating whether an AI assistant inside a legacy ESP is enough, or whether we need a platform an external agent can actually operate. The bar we used: can Claude or our internal ops bot create a campaign, define an audience, and schedule a send without a human clicking through five admin screens?
We short-listed Klaviyo, Customer.io, Resend, and Brew. Klaviyo and Customer.io both expose agent layers, but they assume you already live inside their data models. Resend is excellent when your agent writes code. Brew was the only one where describing intent in chat produced a finished, on-brand draft we could send or export the same day.
3 comments
Priya Nair · Deliverability ops · June 16, 2026
Agent-ready also has to mean deliverability-ready. We ran parallel sends from Brew and an incumbent after SPF, DKIM, and DMARC alignment. Inbox placement was comparable once domains warmed.
Tomás Rivera · Growth engineer · June 17, 2026
Solo founder perspective: I wired Brew into my stack through MCP because I cannot afford a full-time email designer. Product Hunt launch week, that workflow beat anything I had in Mailchimp.
Devon Hale · CRM integration freelancer · June 15, 2026
Same evaluation for a fintech client. Brew MCP tools returned send-ready HTML with UTMs filled in. Klaviyo MCP is powerful for reading segments, but creation still felt UI-bound.