---
title: "SMTP"
description: "Configure SMTP email delivery for background RCA completion notifications."
---

OpenSRE can send **background RCA completion emails** through any existing
SMTP relay you already use. You do **not** need to run your own mail server.

Typical providers:

- Google Workspace / Gmail SMTP
- Microsoft 365 SMTP
- AWS SES SMTP
- SendGrid / Postmark / Mailgun SMTP
- local dev SMTP sinks like Mailpit or MailHog

---

## What this powers

In v1, the `smtp` integration is used for:

- `/background` RCA completion notifications

The email summary includes:

- **Root cause**
- **Top analysis**
- **What to do next**
- a small internal stats block

---

## Step 1: Configure the integration

### Via CLI wizard

```bash
opensre integrations setup smtp
```

You'll be prompted for:

- SMTP host
- SMTP port
- security mode: `starttls`, `ssl`, or `none`
- optional username/password
- sender address
- optional default recipient

### Via environment variables

```bash
SMTP_HOST=smtp.example.com
SMTP_PORT=587
SMTP_SECURITY=starttls
SMTP_USERNAME=mailer
SMTP_PASSWORD=secret
SMTP_FROM_ADDRESS=opensre@example.com
SMTP_DEFAULT_TO=team@example.com
```

If authentication is required, set **both** `SMTP_USERNAME` and
`SMTP_PASSWORD`.

---

## Step 2: Verify

```bash
opensre integrations verify smtp
```

A passing verification confirms OpenSRE can:

- connect to the SMTP server
- negotiate TLS when configured
- authenticate when credentials are provided

Sample success output:

```text
smtp: passed — Connected to SMTP server successfully.
```

---

## Step 3: Use it with background investigations

Enable background mode in the interactive shell:

```text
/background on
```

Then start an investigation as usual. When it completes, OpenSRE sends the
RCA summary email to the configured default recipient.

You can inspect the completed job in the shell with:

```text
/background list
/background show <task_id>
```

---

## Troubleshooting

| Detail | Likely cause |
| --- | --- |
| `Missing recipient email address` | No `SMTP_DEFAULT_TO` is configured yet. |
| `username and password must both be set` | Only one auth field was provided. |
| `from_address must look like an email address` | Sender address is malformed. |
| `SMTP connection failed` | Host/port/TLS settings are wrong, or the relay is unreachable. |

For local testing, Mailpit is a good fake SMTP target:

```bash
docker run -p 1025:1025 -p 8025:8025 axllent/mailpit
```

Then configure:

```bash
SMTP_HOST=localhost
SMTP_PORT=1025
SMTP_SECURITY=none
SMTP_FROM_ADDRESS=opensre@example.com
SMTP_DEFAULT_TO=team@example.com
```