SMTP

Configure SMTP email delivery for background RCA completion notifications.

Overview

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

In v1, the smtp integration is used for /background RCA completion notifications. Email is one of the completion channels — Telegram is another, and you can enable both at once. See Background investigations.

The email summary includes:

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

Prerequisites

• An SMTP host you can reach from OpenSRE
• A sender address the relay will accept
• Optional username/password if the relay requires auth

Setup

Option 1: CLI wizard

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

SMTP is not in the onboard Incident & Comms list — use this setup command.

Option 2: Environment variables

SMTP_HOST=smtp.example.com
SMTP_PORT=587
SMTP_SECURITY=starttls
SMTP_USERNAME=mailer
SMTP_PASSWORD=secret
SMTP_FROM_ADDRESS=[e-mail]
SMTP_DEFAULT_TO=[e-mail]

Variable	Default	Description
SMTP_HOST	—	SMTP hostname
SMTP_PORT	587	SMTP port
SMTP_SECURITY	starttls	starttls, ssl, or none
SMTP_USERNAME	—	Optional auth username (set with password)
SMTP_PASSWORD	—	Optional auth password (set with username)
SMTP_FROM_ADDRESS	—	Sender address
SMTP_DEFAULT_TO	—	Default recipient for background emails

If authentication is required, set both SMTP_USERNAME and SMTP_PASSWORD.

Credentials

Use any SMTP relay your org already trusts. For local testing, Mailpit is a good fake SMTP target:

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

SMTP_HOST=localhost
SMTP_PORT=1025
SMTP_SECURITY=none
SMTP_FROM_ADDRESS=[e-mail]
SMTP_DEFAULT_TO=[e-mail]

Investigation tools

No SMTP investigation tools are registered. Email delivery is used for /background RCA completion notifications when the email channel is selected.

Use it with background investigations

Notification channels are empty by default, so /background on on its own sends nothing:

/background on
/background notify set email
/background notify list   # -> email

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

To send the same summary to Telegram as well:

/background notify set email,telegram

Inspect completed jobs with:

/background list
/background show <task_id>

Verify

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:

smtp: passed — Connected to SMTP server successfully.

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.

Security

• Prefer app passwords / SMTP credentials scoped to a mailer account.
• Store passwords in .env or your secret manager — not in source control.
• Use starttls or ssl in production; reserve none for local sinks.