Plug into your stack,
not around it.

App Router-native SDK with React Email templates rendered server-side.

Loader/action-friendly SDK + Mailer abstraction.

ActionMailer adapter + Active Job background sending.

Mail driver + Notification channel.

EMAIL_BACKEND drop-in + Celery task helpers.

Async client with Pydantic-validated payloads.

Trigger flows on every email event. Send from any of 7,000 apps.

Visual scenario builder — webhook → email → branch.

Self-hostable. Same trigger / action surface as Zapier.

Code-first workflow runner. JS / Python steps wrap volt.send().

Receipts, dunning, subscription notifications — wired in 4 lines.

License-key delivery, receipts, dunning for indie SaaS.

Tax-compliant receipts. EU + UK invoice templates included.

Order confirmation, shipping, abandoned cart.

Two-way sync of contacts + email events to the HubSpot timeline.

Lead + Contact sync via OAuth + bulk API.

Person + Deal sync. Email-event sync to the Activity feed.

Modern CRM with deep object model — sync People + Companies + Lists.

Source + Destination — fan in user events, fan out email events.

Open-source CDP — event source + send destination.

Trigger sends from PostHog cohorts. Capture email events back as user properties.

Event ingest + cohort sync.