Rails mail to a local inbox shared by all your apps

1. Start Buggregator

Run the container. Port 8000 is the web UI, port 1025 is the SMTP server.

docker run --pull always \
  -p 127.0.0.1:8000:8000 \
  -p 127.0.0.1:1025:1025 \
  -p 127.0.0.1:9912:9912 \
  -p 127.0.0.1:9913:9913 \
  ghcr.io/buggregator/server:latest

2. Set the SMTP settings for development

Add this to your development environment file. No username, password or TLS setup is needed.

# config/environments/development.rb
config.action_mailer.smtp_settings = {
    address: '127.0.0.1',
    port: 1025,
}

3. Make sure the delivery method is SMTP

Action Mailer's delivery_method defaults to :smtp. If your development file sets another one, for example :letter_opener or :test, change it in the same file:

config.action_mailer.delivery_method = :smtp

4. Send an email and open it

Trigger any mailer, then open http://127.0.0.1:8000. You see the rendered HTML with a desktop/mobile switcher, the plain text version, the addresses, the attachments and the raw MIME source. In Docker Compose, use the Buggregator service name, for example buggregator, instead of 127.0.0.1.

Buggregator includes a fake SMTP server that stores each email instead of delivering it. Any app that can send email over SMTP works with it, so a Rails app, a Laravel app and a Node app can all send to the same inbox.

Sources: Rails guides, Action Mailer configuration and config.action_mailer.delivery_method.