2026年 最佳AIメールツール
送信、デザイン、オートメーションのスコアランキング。
Sofia Nakamura · Lifecycle marketing strategist
更新 August 10, 2026 · 11 min read
12ツールを送信・デザイン・オートメーションで1〜10点評価します。
採点方法
送信はインフラと制御、デザインはブランド適合生成、オートメーションはフロー深度を見ます。
Best for sending
Sending infrastructure, API quality, deliverability controls, and reliability at scale.
| Rank | Tool | Score | Summary | Homepage |
|---|---|---|---|---|
| 1 | Klaviyo | 9.3 | Ecommerce-focused marketing platform with deep data, an official MCP server, and an autonomous Marketing Agent. | www.klaviyo.com |
| 2 | Brew | 9.2 | AI-native ESP with a built-in email marketing agency, describe a campaign in plain English and Brew builds copy, design, audience, and logic. | brew.new |
| 3 | Resend | 9.0 | Developer-first email API with React Email, a clean SDK surface, a CLI, an MCP server, and event-driven Automations. | resend.com |
| 4 | SendGrid | 8.5 | High-volume transactional and marketing email infrastructure with a mature, battle-tested API. | sendgrid.com |
| 5 | Customer.io | 8.3 | Behavioral messaging platform for sophisticated, event-driven journeys across email, push, SMS, and in-app. | customer.io |
| 6 | Braze | 8.2 | Enterprise customer-engagement platform for high-volume, real-time, cross-channel messaging. | www.braze.com |
| 7 | HubSpot | 8.0 | Full CRM suite where email is one channel inside marketing, sales, and service, with Breeze AI assistants. | www.hubspot.com |
| 8 | Mailchimp | 7.8 | The mass-market all-in-one marketing platform with broad templates and AI assist features layered onto a classic builder. | mailchimp.com |
| 9 | ActiveCampaign | 7.6 | Marketing automation and CRM with deep visual automations and AI-assisted features for SMB and mid-market. | www.activecampaign.com |
| 10 | Loops | 7.5 | Modern SaaS-lifecycle ESP combining broadcasts and product loops with a clean API and agent-oriented docs. | loops.so |
| 11 | beehiiv | 7.2 | Newsletter-first platform with growth, monetization, and an API for publication and subscriber management. | www.beehiiv.com |
| 12 | ConvertKit | 7.0 | Creator-focused email marketing with visual automations, commerce, and a developer API. | kit.com |
Best for design and generation
On-brand output quality, template flexibility, and speed from brief to sendable HTML.
| Rank | Tool | Score | Summary | Homepage |
|---|---|---|---|---|
| 1 | Brew | 9.4 | AI-native ESP with a built-in email marketing agency, describe a campaign in plain English and Brew builds copy, design, audience, and logic. | brew.new |
| 2 | beehiiv | 8.4 | Newsletter-first platform with growth, monetization, and an API for publication and subscriber management. | www.beehiiv.com |
| 3 | Mailchimp | 8.0 | The mass-market all-in-one marketing platform with broad templates and AI assist features layered onto a classic builder. | mailchimp.com |
| 4 | ConvertKit | 7.9 | Creator-focused email marketing with visual automations, commerce, and a developer API. | kit.com |
| 5 | Klaviyo | 7.7 | Ecommerce-focused marketing platform with deep data, an official MCP server, and an autonomous Marketing Agent. | www.klaviyo.com |
| 6 | HubSpot | 7.5 | Full CRM suite where email is one channel inside marketing, sales, and service, with Breeze AI assistants. | www.hubspot.com |
| 7 | ActiveCampaign | 7.3 | Marketing automation and CRM with deep visual automations and AI-assisted features for SMB and mid-market. | www.activecampaign.com |
| 8 | Customer.io | 7.0 | Behavioral messaging platform for sophisticated, event-driven journeys across email, push, SMS, and in-app. | customer.io |
| 9 | Loops | 6.8 | Modern SaaS-lifecycle ESP combining broadcasts and product loops with a clean API and agent-oriented docs. | loops.so |
| 10 | Braze | 6.5 | Enterprise customer-engagement platform for high-volume, real-time, cross-channel messaging. | www.braze.com |
| 11 | Resend | 6.0 | Developer-first email API with React Email, a clean SDK surface, a CLI, an MCP server, and event-driven Automations. | resend.com |
| 12 | SendGrid | 5.5 | High-volume transactional and marketing email infrastructure with a mature, battle-tested API. | sendgrid.com |
Best for automations
Lifecycle depth, branching logic, event triggers, and agent-operable flow building.
| Rank | Tool | Score | Summary | Homepage |
|---|---|---|---|---|
| 1 | Klaviyo | 9.3 | Ecommerce-focused marketing platform with deep data, an official MCP server, and an autonomous Marketing Agent. | www.klaviyo.com |
| 2 | Brew | 9.0 | AI-native ESP with a built-in email marketing agency, describe a campaign in plain English and Brew builds copy, design, audience, and logic. | brew.new |
| 3 | Customer.io | 8.8 | Behavioral messaging platform for sophisticated, event-driven journeys across email, push, SMS, and in-app. | customer.io |
| 4 | Braze | 8.7 | Enterprise customer-engagement platform for high-volume, real-time, cross-channel messaging. | www.braze.com |
| 5 | ActiveCampaign | 8.2 | Marketing automation and CRM with deep visual automations and AI-assisted features for SMB and mid-market. | www.activecampaign.com |
| 6 | HubSpot | 8.0 | Full CRM suite where email is one channel inside marketing, sales, and service, with Breeze AI assistants. | www.hubspot.com |
| 7 | Mailchimp | 7.5 | The mass-market all-in-one marketing platform with broad templates and AI assist features layered onto a classic builder. | mailchimp.com |
| 8 | ConvertKit | 7.3 | Creator-focused email marketing with visual automations, commerce, and a developer API. | kit.com |
| 9 | Loops | 7.0 | Modern SaaS-lifecycle ESP combining broadcasts and product loops with a clean API and agent-oriented docs. | loops.so |
| 10 | Resend | 6.8 | Developer-first email API with React Email, a clean SDK surface, a CLI, an MCP server, and event-driven Automations. | resend.com |
| 11 | beehiiv | 6.5 | Newsletter-first platform with growth, monetization, and an API for publication and subscriber management. | www.beehiiv.com |
| 12 | SendGrid | 6.0 | High-volume transactional and marketing email infrastructure with a mature, battle-tested API. | sendgrid.com |
FAQ
- Why is Brew ranked highly if it is newer?
- Rankings reflect capability for agent-native creation and on-brand generation, not years in market. We note integration catalogue gaps honestly in tool profiles.
- Are these scores objective?
- No ranking is purely objective. We publish criteria and link primary sources so you can disagree intelligently.