Email Automation
Email marketing and automation platforms, spanning campaign and lifecycle marketing tools, behavioural automation, and transactional email delivery APIs.
Email automation covers two distinct kinds of product that are often grouped together because they share a delivery channel.
The first is marketing and lifecycle automation. Tools in this group hold a contact database, segment it by attributes and behaviour, and run multi-step sequences triggered by what a contact does: signing up, abandoning a cart, going quiet for ninety days. ActiveCampaign, ConvertKit (Kit), Drip, and Constant Contact sit here. Pricing in this group is almost always tiered by contact count rather than by send volume, which means the cost of an inactive subscriber is the same as the cost of an engaged one.
The second is transactional and programmatic delivery. These are APIs rather than campaign builders: an application calls them to send a receipt, a password reset, or a notification, one message at a time. SendGrid, Mailgun, Postmark, and Resend sit here. Pricing is by message volume, deliverability and sender reputation are the main differentiators, and there is usually no contact database at all.
The distinction matters when choosing a tool because the two groups fail in different ways. A marketing platform used for transactional mail tends to introduce latency and deliverability risk, since transactional messages compete with bulk campaign sends on the same reputation. A transactional API used for marketing lacks segmentation, consent management, and the unsubscribe handling that marketing regulation expects. Teams running both usually keep them on separate providers and separate sending domains.
General-purpose automation platforms such as Zapier, Make, and n8n connect to tools in both groups rather than replacing them. Their role is moving contact and event data between an email platform and the systems that hold the rest of the customer record, most often a CRM, a billing system, or a data warehouse.
8 tools in this category
Quick Comparison
| Tool | Pricing Model | Free Tier | Open Source | Self-Hostable |
|---|---|---|---|---|
| ActiveCampaign | paid | No | No | No |
| Constant Contact | paid | No | No | No |
| ConvertKit (Kit) | freemium | Yes | No | No |
| Drip | paid | No | No | No |
| Mailgun | paid | No | No | No |
| Postmark | paid | No | No | No |
| Resend | freemium | Yes | No | No |
| SendGrid | freemium | Yes | No | No |
ActiveCampaign
Email marketing, marketing automation, and CRM tools you will actually use
Constant Contact
Email marketing platform since 1995 with drag-and-drop editor, automations, landing pages, and social media marketing.
ConvertKit (Kit)
Creator-focused email marketing platform with visual automations, landing pages, and digital commerce features.
Drip
Ecommerce email and SMS marketing platform with visual workflows, revenue attribution, and deep Shopify integration.
Mailgun
Transactional email API from Sinch with SMTP relay, inbound routing, email validation, and deliverability analytics.
Postmark
Developer-focused transactional email API with separated transactional and broadcast streams, templates, and fast delivery.
Resend
Developer-first transactional email API with React-based templates and audience management.
SendGrid
Email delivery API and marketing platform acquired by Twilio, handling billions of emails monthly with high deliverability.
Email Automation Rankings
Questions About Email Automation
What does the Resend free tier include in 2026?
As of July 2026, the Resend free tier includes 3,000 emails/month, 100 emails/day, one verified domain, 30-day email log retention, and basic webhooks. It is intended for development, testing, and very small production sends; teams typically upgrade to the $20/month Pro plan…
How do you migrate from SendGrid to Resend in 2026?
A SendGrid-to-Resend migration in 2026 follows five steps: verify domains in Resend, port templates (Resend recommends React Email), swap the API client in code, run dual-send for a verification window, and update DNS to point all sending traffic to Resend. Most production…
What's the difference between Resend, SendGrid, and Postmark?
Resend is a React-template developer-first email API from 2023 with 3,000 free emails/month and $20/month for 50K. SendGrid is the high-scale market leader from 2009 (Twilio) with marketing plus transactional from $19.95/month. Postmark is the deliverability specialist from 2010…
What is the best email automation platform in 2026?
The top email automation platforms in 2026 are [Klaviyo](/tools/klaviyo/) (e-commerce leader on Shopify), [Mailchimp](/tools/mailchimp/) (broadest SMB reach), and [ActiveCampaign](/tools/activecampaign/) (deep visual automations with built-in CRM).
Email Automation Guides
How to Automate Customer Onboarding Emails with Klaviyo
A tutorial for building a 5-email customer onboarding sequence in Klaviyo. Covers trigger configuration, email content strategy for each stage (welcome, quick win, feature discovery, social proof, feedback), conditional splits, A/B testing, and performance monitoring with data…
Drip vs Klaviyo: Complete Comparison (2026)
A comparison of Drip and Klaviyo for ecommerce email marketing in 2026. Drip offers simpler automation at 35% lower cost for small lists (2,500 contacts). Klaviyo provides predictive analytics, SMS, and deeper Shopify integration with prices converging at 10,000+ contacts…