Feature deep dive

SMTP Service

A drop-in SMTP relay for teams that prefer standard mail-client integrations. Same backend delivery engine, same tracking and analytics — just connect over SMTP instead of REST.

How it works

  • Use your API key as the SMTP password — no extra credentials needed.
  • Permission scopes are validated before any message is accepted.
  • MIME is parsed and fed into the same queue-backed send pipeline.
  • Tracking, analytics, and webhooks work identically to REST sends.

Capabilities

  • Standard SMTP relay — works with any language, framework, or email client.
  • Authenticate with your Sendr API key as the SMTP password.
  • Same delivery pipeline as the REST API — queuing, tracking, and analytics included.
  • Scope-aware auth enforces sending permissions before accepting messages.
  • Full MIME parsing — From, To, CC, BCC, subject, body, and attachments.
  • Domain verification and suppression filters applied automatically.
  • Shared delivery policies and rate limits across SMTP and REST sends.

Connection settings

Host

smtp.sendr.dev

Port

2525 (TLS)

Username

Any string (e.g. apikey)

Password

Your Sendr API key

Encryption

STARTTLS required

Auth method

PLAIN or LOGIN

Works with any SMTP client, language, or framework. Use your existing API key — no extra credentials needed.

Prefer REST workflows or inbound processing?

Explore related send and receive paths in the platform.