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Security

Controls, not assurances.

This page lists mechanisms that exist in the product, and says plainly where a control is a plan-level commitment rather than code. If something below is not precise enough for your review, ask — we would rather answer than have you infer.

01 · Authentication & access
API keys
Bearer tokens, scoped to a whole workspace or to a single domain, with a last-used timestamp so stale keys are visible.
Rate limiting
60 requests per minute and 1,000 per hour per key, returned as a readable 429 rather than a silent drop.
Idempotency
An Idempotency-Key header makes a send replay-safe for 24 hours, so a retry storm cannot duplicate mail.
Sessions
Every active session is listed with its IP and user agent, and can be revoked individually.
Roles
Workspace owners and members, with teammate management scoped per workspace.
02 · Sending integrity
Domain verification
Mail only leaves for domains you have proven you control, via generated DKIM, SPF, and DMARC records.
DKIM signing
Per-domain keys, selector `mail`, generated on our side and published by you in DNS.
Region control
Each domain sends from the AWS region you choose, so data residency is a setting rather than a support ticket.
Reputation enforcement
Reputation is scored per domain and per workspace; a workspace that crosses the line is disabled automatically and its queued mail fails loudly.
Suppression lists
Held per stream, so a transactional unsubscribe does not silently kill a broadcast, or the reverse.
03 · Webhooks & data
Signed payloads
Every endpoint gets its own HMAC secret; verify the signature over the raw body before trusting anything in it.
Delivery log
Attempts, response codes, and response bodies are stored per delivery, so a failing endpoint is diagnosable rather than mysterious.
Raw payloads
We keep the provider's original event payload alongside our normalised version. Normalisation is never the only record.
Retention
Event retention is the same on every cloud plan, and configurable on Dedicated.
Transport
TLS everywhere: HTTPS for the API, STARTTLS on the SMTP relay.
04 · Regulated workloads

HIPAA and the honest version.

We do not call Outsend “HIPAA-compliant,” because no platform is compliant by itself — it takes a signed Business Associate Agreement and documented controls on both sides. A BAA is available on the Dedicated plan, on request, where sending is isolated. We do not offer one on shared plans: a BAA over a shared pool would be a document rather than a control.

We do not ask for, want, or knowingly store protected health information in message content we retain. If your use case requires content retention limits, say so before you start and we will configure it rather than discover it later.

Ask us firstBAA terms, retention limits, and residency are all settled in writing before you send.

05 · Reporting a vulnerability

Email security@getoutsend.com with enough detail to reproduce the issue. We will acknowledge within two business days and tell you what we found, including if we disagree that it is a vulnerability.

Please do not test against other people's workspaces or send mail you are not authorised to send.

Bring your security review.

We would rather answer a hard questionnaire than have you assume the generous interpretation.

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