Concepts
Delivery Engines

Delivery Engines

The delivery engine controls how PING8 injects and transports messages.

Choose the engine based on your volume, operational maturity, and infrastructure.

Engine options

EngineUse whenAvoid when
Local PostfixYou are testing a small self-hosted setup or sending low volume.You need advanced pool routing, high volume, or rich MTA telemetry.
Tenant defaultYou want PING8 to use the workspace's configured default sending profile.The tenant default profile has not been configured or tested.
KumoMTAYou run a KumoMTA path and need high-volume control, queue visibility, and webhooks.DNS, TLS, injection auth, or event callbacks are not verified.
External SMTPYou need to relay through a third-party SMTP account.You need full KumoMTA queue and provider telemetry.

Recommended path

  1. Use Local Postfix only for initial low-volume self-host testing.
  2. Configure and test a tenant default delivery profile.
  3. Use Tenant default for day-to-day sending once it is healthy.
  4. Use KumoMTA directly only when validating a specific MTA path.

Before switching engines

Check:

  • The sender domain is verified.
  • The From address belongs to the domain.
  • The engine is enabled for the send type you are using.
  • The sending profile is ready or tenant default resolves correctly.
  • You can see lifecycle events after a one-recipient test.

Common mistakes

  • Using Local Postfix for a marketing campaign when the intended production path is KumoMTA.
  • Selecting KumoMTA before the webhook path is verified.
  • Leaving a sending profile unset when tenant defaults have not been configured.
  • Testing only Gmail and assuming every recipient provider behaves the same.

Related pages