This PR adds a fake SMTP server for scale testing. It collects emails sent during tests, which you can then check using the HTTP API.

Changes

• Added mock SMTP server
• Addedcoder scaletest smtp CLI command
• Implemented HTTP API endpoints to retrieve messages by email
• Added auto-purge to prevent memory issues

HTTP API Endpoints

• GET /messages?email=<email> – Get messages sent to an email address
• POST /purge – Clear all messages from memory

The HTTP API parses raw email messages to extract thedate,subject, andnotification ID.

Notification IDs are sent in emails like this:

<p><ahref="http://127.0.0.1:3000/settings/notifications?disabled=4e19c0ac-94e1-4532-9515-d1801aa283b2"style="color: #2563eb; text-decoration: none;">    Stop receiving emails like this</a></p>

CLI

coder scaletest smtp --host localhost --port 33199 --api-port 8080 --purge-at-count 1000

Flags:

• --host: Host for the mock SMTP and API server (default: localhost)
• --port: Port for the mock SMTP server (random if not specified)
• --api-port: Port for the HTTP API server (random if not specified)
• --purge-at-count: Max number of messages before auto-purging (default: 100000)