Email Execution Layer

Everything between your code and the inbox.

Truncus is the infrastructure layer below your email API. Deterministic delivery, a durable retry queue, governance, and EU-only processing — in one integration.

Execution

Know what happened to every email. Not “accepted” — delivered, bounced, or rejected.

send_sync

Synchronous delivery confirmation. One API call, one definitive answer: delivered, bounced, or rejected. Average 1.04s.

Operations API

Durable operations with delivery guarantees: best_effort, at_least_once, exactly_once. Truncus handles retries.

Terminal states

Every email reaches a terminal state — delivered, bounced, or rejected. No "accepted" limbo. You always know what happened.

Failure intelligence

When delivery fails, Truncus explains why (ISP block, full mailbox, invalid MX) and recommends a specific action.

Reliability

When a send fails, you find out immediately — and transient failures retry on their own.

Durable retry queue

Transient failures are retried with backoff from a durable queue. Nothing is dropped on the floor when a send doesn’t go through first time.

Circuit breakers

Failure-rate monitoring on the SES Ireland path. When errors spike, the circuit opens and surfaces the exact error — fail-fast, no silent failures.

Replay

Replay failed deliveries from the event log without resending. Operational resilience without duplicate emails.

99.5% SLA

API uptime commitment with credit schedule. Pro and Scale plans.

Governance

Control who sends what, from which domain, and stop it instantly when something goes wrong.

Stream isolation

Transactional and outreach traffic run on isolated domains with separate reputations. Hard API enforcement.

Kill switch

Instantly revoke sending access for any domain, API key, or traffic type. Takes effect in under a second.

Account reputation

Bounce and complaint rates tracked per account. Automatic throttling and suspension when thresholds are exceeded.

Pre-send validation

Confidence scoring, spam risk check, and domain health assessment before the email leaves your infrastructure.

Infrastructure

EU-hosted, encrypted, GDPR-ready. Built for teams that need to pass security review.

EU-only delivery

Email delivery processed exclusively in AWS SES eu-west-1 (Ireland). No international transfer for email content.

TLS + AES-256

All data encrypted in transit (TLS) and at rest (AES-256). API keys hashed with SHA-256, never stored in plain text.

Webhooks

Real-time delivery events via signed webhooks. Delivery, bounce, complaint, open, and click events.

Idempotency

Content deduplication with SHA-256 hashing in a 10-minute window. Safe retries without duplicate sends.

Set up your domain in under a minute

Free tier includes 3,000 emails/month. No credit card required.

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Features — Truncus Email Execution Layer