Ingestion

There is currently no total number limit for inbox items, but there are limits on the number of ingestions per month. Each time an email, SMS or other payload is ingested into your inbox, it counts towards your monthly ingestion limit. The limit resets at the start of each month.

However, there is a retention and storage limit that automatically deletes inbox items after a certain amount of time, but this is not related to the ingestion limits.

SMTP Ingestion

Capture outbound emails via SMTP and store them in your Sinkbox inbox.

SMS API Ingestion

Use our API to capture incoming SMS messages and store them in your Sinkbox inbox.

Dump Ingestion

Capture full HTTP request dumps from any webhook or client using a single ingest endpoint.

Drop-in service endpoints

Drop-in endpoints let you replace a real third-party API with Sinkbox during development and testing. Simply point your SDK or HTTP client at your Sinkbox base URL and all outgoing messages are silently captured in your inbox instead of being delivered.

Each drop-in URL embeds your Sinkbox project credentials directly in the path:

POST https://ingest.sinkbox.app/dropin/{username}/{key}/{service}/{version}/{type}

The {username} and {key} segments are the credentials from your project API key. No additional authentication headers are required — Sinkbox reads the credentials from the URL path and ignores any service-specific auth headers your SDK may add.

Supported services

Currently 13 drop-in endpoints are available for popular email, SMS, push notification, and webhook services, with more to come.

Override the base URL (or the SDK-specific environment variable) in your application to start capturing: