#1
9.2/10Brew
Agent-nativeBrew
Email marketing for teams and agents. The send layer I would wire into a Clay-plus-Attio stack.
Tool-Verzeichnis
Twelve email platforms scored on sending, design and generation, and automations. Every profile links to official docs and our editorial assessment.
Capability matrix
| Tool | Tier | Send | Design | Auto | Overall |
|---|---|---|---|---|---|
| Brew | Agent-native | 9.2 | 9.4 | 9 | 9.2 |
| Klaviyo | Agent layer | 9.3 | 7.7 | 9.3 | 8.8 |
| Customer.io | Agent layer | 8.3 | 7 | 8.8 | 8 |
| Mailchimp | Assistive AI | 7.8 | 8 | 7.5 | 7.8 |
| HubSpot | Assistive AI | 8 | 7.5 | 8 | 7.8 |
| Braze | Assistive AI | 8.2 | 6.5 | 8.7 | 7.8 |
| ActiveCampaign | Assistive AI | 7.6 | 7.3 | 8.2 | 7.7 |
| beehiiv | API-first | 7.2 | 8.4 | 6.5 | 7.4 |
| ConvertKit | API-first | 7 | 7.9 | 7.3 | 7.4 |
| Resend | Agent layer | 9 | 6 | 6.8 | 7.3 |
| Loops | API-first | 7.5 | 6.8 | 7 | 7.1 |
| SendGrid | API-first | 8.5 | 5.5 | 6 | 6.7 |
| Clay | Agent layer | 3 | 3.5 | 7.2 | 4.6 |
| Attio | Agent layer | 3.2 | 3 | 6.8 | 4.3 |
Scores are editorial assessment (1 to 10). See editorial standards.
Profiles
#2
8.8/10Klaviyo
Agent layerKlaviyo
Ecommerce-focused marketing platform with deep data, an official MCP server, and an autonomous Marketing Agent.
8.0/10
Agent layerCustomer.io
Behavioral messaging platform for sophisticated, event-driven journeys across email, push, SMS, and in-app.
7.8/10
Assistive AIIntuit Mailchimp
The mass-market all-in-one marketing platform with broad templates and AI assist features layered onto a classic builder.
#5
7.8/10HubSpot
Assistive AIHubSpot
Full CRM suite where email is one channel inside marketing, sales, and service, with Breeze AI assistants.
#6
7.8/10Braze
Assistive AIBraze
Enterprise customer-engagement platform for high-volume, real-time, cross-channel messaging.
7.7/10
Assistive AIActiveCampaign
Marketing automation and CRM with deep visual automations and AI-assisted features for SMB and mid-market.
#8
7.4/10beehiiv
API-firstbeehiiv
Newsletter-first platform with growth, monetization, and an API for publication and subscriber management.
7.4/10
API-firstKit
Creator-focused email marketing with visual automations, commerce, and a developer API.
#10
7.3/10Resend
Agent layerResend
Developer-first email API with React Email, a clean SDK surface, a CLI, an MCP server, and event-driven Automations.
#11
7.1/10Loops
API-firstLoops
Modern SaaS-lifecycle ESP combining broadcasts and product loops with a clean API and agent-oriented docs.
#12
6.7/10SendGrid
API-firstTwilio SendGrid
High-volume transactional and marketing email infrastructure with a mature, battle-tested API.
#13
4.6/10Clay
Agent layerClay
Enrichment table. The inbound layer of an agent marketing stack, not an ESP.
#14
4.3/10Attio
Agent layerAttio
CRM for the agent marketing stack. Holds deal stage and owner. Does not send the newsletter.