---
description: Inject messages into KumoMTA over HTTP using a configured HTTP listener, controlling the IPs and ports available for message submission via the API.
---

# Injecting Using HTTP

KumoMTA will listen for message injection in any
[listener](../..//reference/kumo/start_esmtp_listener/index.md)
[defined](../../reference/kumo/start_http_listener/index.md) in
configuration. You have complete control over the IPs and Ports available for
message injection.

The HTTP Listener will accept any properly formatted HTTP connection request
allowed by its configuration.  For instance, based on this:

```lua
kumo.start_http_listener {
  use_tls = true,
  listen = '0.0.0.0:8005',
  -- allowed to access any http endpoint without additional auth
  trusted_hosts = { '127.0.0.1', '::1' },
}
```

KumoMTA will accept any HTTPS injection on port 8005 from the local host ONLY.
(This also enables the full [HTTP API](../../reference/http/kumod/index.md) from
localhost).


The simplest test of [HTTP injection](../../reference/http/kumod/api_inject_v1_post.md)
can be done using curl right from the localhost console. Note the `-k`
option: it lets curl accept the self-signed certificate that KumoMTA
generates when no TLS certificate is configured for the listener.

```console
$ curl -ik 'https://localhost:8005/api/inject/v1' \
 -H 'Content-Type: application/json' -d '
{"envelope_sender": "noreply@example.com",
 "content": "Subject: hello\n\nHello there",
 "recipients": [{"email": "recipient@example.com"}]
}'
```

That should return something like this:

```json
{"success_count":1,"fail_count":0,"failed_recipients":[],"errors":[]}
```

Any system that can use an HTTP API to pass JSON should work as an injection
system if you follow the JSON payload formatting rules posted
[here](../..//reference/http/kumod/api_inject_v1_post.md)