PostHog gives you product analytics, feature flags, session replays, and experiments in one open-source package. What it doesn't give you is email. And if you're building a product-led SaaS, the gap between "knowing what users do" and "emailing them about it" is where a lot of growth happens.

The good news is that PostHog tracks the exact events you'd want to trigger emails on: user signed up, feature used, trial expiring, onboarding step completed. The challenge is getting those events into an email platform that can actually do something with them.

Here's how the best email tools connect with PostHog.

How PostHog + Email Integration Works

PostHog doesn't have a native email sending feature (they've said they won't build one). So you need to get PostHog data into an email tool. There are three main approaches:

Webhooks from PostHog Actions: PostHog can fire a webhook when an Action triggers. Set up an Action for the event you care about, add a webhook destination, and point it at your email platform's API.
PostHog CDP (Customer Data Platform): PostHog's CDP feature lets you route events to destinations including email platforms. This is the cleanest approach for real-time event routing.
Shared event tracking: Track events to both PostHog and your email tool from your application code. This is the most common approach since you control exactly what goes where.
Batch exports: Export PostHog cohorts periodically and sync them to your email platform's segments. Less real-time but works for campaign-based use cases.

The 6 Best Options

1. Sequenzy

Best for: SaaS founders wanting PostHog events to drive lifecycle email

Sequenzy's event API accepts the same kinds of events PostHog tracks. The integration pattern is straightforward: track events to both PostHog (for analytics) and Sequenzy (for email automation) from your application code. When a user completes onboarding, hits a usage milestone, or triggers a billing event, Sequenzy starts the right email sequence.

The overlap between PostHog users and Sequenzy users is natural. Both tools target developers building SaaS products. Both are event-driven. And Sequenzy's Stripe integration handles payment events automatically, so you only need to manually track product usage events.

Pricing: From $29/month Integration: Shared event tracking from application code, or PostHog webhook to Sequenzy API Pros: Event-driven like PostHog, SaaS lifecycle focus, Stripe handles payment events, simple API Cons: No native PostHog destination, newer platform

2. Customer.io

Best for: Technical teams wanting the deepest event-driven email automation

Customer.io is the most event-driven email platform on the market, which makes it a natural pairing with PostHog. You can route PostHog events to Customer.io via the PostHog CDP, webhooks, or shared application-level tracking.

Once events arrive in Customer.io, the automation possibilities are extensive. Trigger campaigns based on event combinations, use event properties for personalization, build complex branching workflows. If PostHog is your analytics brain, Customer.io can be your email brain.

Pricing: From $100/month Integration: PostHog CDP destination, webhooks, or shared event tracking Pros: Most flexible automations, deep event handling, visual workflow builder, API-first Cons: Expensive, steep learning curve, can be overengineered for simple needs

3. Loops

Best for: Early-stage SaaS wanting simple event-to-email automation

Loops is built for the same audience that loves PostHog: developers building SaaS products. The integration works through shared event tracking. Track events to PostHog for analytics and to Loops for email triggers. Loops' event model is simple and maps well to PostHog events.

The simplicity is the selling point. Where Customer.io gives you a visual workflow builder with dozens of options, Loops gives you event-triggered sequences that just work. For a startup that wants "when user does X, send email Y" without building a complex automation engine, Loops delivers.

Pricing: Free for 1,000 contacts, from $49/month Integration: Shared event tracking from application code Pros: Simple, developer-friendly, good free tier, event-driven model Cons: Basic automations, limited segmentation, no direct PostHog integration

4. Resend

Best for: Developers wanting PostHog analytics with clean transactional email

Resend handles transactional email (welcome emails, password resets, notifications) with the best developer experience available. Combined with PostHog, you get analytics on user behavior plus reliable email delivery for the messages that matter most.

The integration is at the application level: your app tracks events to PostHog and sends emails via Resend in the same request handlers. Resend doesn't have automations or sequences, so it's purely for transactional email. You'd need a separate tool for marketing and lifecycle emails.

Pricing: Free for 100 emails/day, from $20/month Integration: Application-level (both called from your code) Pros: Best DX, React Email, TypeScript-first, fast delivery Cons: No automations, no marketing email, transactional only

5. Brevo (formerly Sendinblue)

Best for: Teams wanting an affordable all-in-one alongside PostHog

Brevo offers email, SMS, and basic automation at a lower price point than most competitors. You can route PostHog events to Brevo via webhooks or application-level tracking. Brevo's automation workflows can trigger on custom events, though the event handling isn't as sophisticated as Customer.io.

The value proposition is breadth at a low price. If you need email marketing, transactional email, and SMS alongside PostHog analytics, Brevo covers all three without enterprise pricing.

Pricing: Free for 300 emails/day, from $9/month Integration: Webhooks or shared event tracking Pros: Affordable, transactional + marketing, SMS included, generous free tier Cons: Less polished than focused tools, automation depth limited, UI can feel clunky

6. Mailgun

Best for: Developers wanting PostHog analytics with reliable email infrastructure

Mailgun provides email infrastructure (sending APIs, deliverability tools, inbound processing) that pairs with PostHog as a pure analytics layer. Your app uses PostHog to understand user behavior and Mailgun to send the resulting emails.

Mailgun is infrastructure, not a marketing platform. There are no visual editors, no drag-and-drop automations, no campaign builders. You build everything in code. For developers who prefer that approach, the PostHog + Mailgun combination gives you analytics and email without any marketing platform overhead.

Pricing: Free for 100 emails/day, from $15/month (Flex plan) Integration: Application-level (both called from your code) Pros: Developer-focused, reliable infrastructure, good APIs, inbound email processing Cons: No marketing features, everything built in code, no automations

Integration Patterns

Pattern 1: Shared Event Tracking (Most Common)

Your application code tracks events to both PostHog and your email tool:

User action -> Your app -> PostHog (analytics) + Email tool (automation)

This is the most reliable approach. You control exactly what data goes where, and there's no dependency between the two services.

Pattern 2: PostHog CDP Routing

PostHog's CDP routes events to your email tool as a destination:

User action -> PostHog -> CDP -> Email tool

Cleaner instrumentation (one tracking call instead of two), but adds a dependency on PostHog's CDP infrastructure. Works well for Customer.io and other tools with CDP support.

Pattern 3: PostHog Webhooks

PostHog fires webhooks when specific Actions trigger:

User action -> PostHog -> Action triggers -> Webhook -> Email tool API

Good for specific, high-value events (trial started, subscription cancelled) rather than high-volume event streaming.

How to Choose

You're a SaaS founder wanting lifecycle email: Sequenzy. Track product events to both PostHog and Sequenzy. Let Stripe handle payment events automatically.

You need complex event-driven automations: Customer.io. The deepest automation engine paired with PostHog's analytics gives you full control.

You want simple and fast: Loops. Event-driven email without the complexity.

You only need transactional email: Resend. Best DX for sending individual emails alongside PostHog analytics.

You want everything cheap: Brevo. Email, SMS, and basic automation at the lowest price point.

You want pure infrastructure: Mailgun. APIs for sending, PostHog for analytics, everything in code.

FAQ

Can PostHog send emails directly? No. PostHog is explicitly a product analytics tool and has stated they won't build email sending. You need a separate email platform.

Should I track events twice (PostHog + email tool)? For most teams, yes. It's the simplest, most reliable approach. The alternative is routing events through PostHog's CDP, which works but adds complexity and a dependency.

Can I use PostHog cohorts for email targeting? You can export PostHog cohorts and import them into your email platform as segments. This works for campaign-based targeting but isn't real-time. For real-time triggers, use event-based automations.

What events should I send to my email tool? Only events that trigger emails or update contact profiles. Your email tool doesn't need page views, button clicks, or session data. Focus on: account created, trial started, onboarding step completed, feature first used, subscription changed, and similar high-value events.