[](https://www.elegantobjects.org) [](http://www.rultor.com/p/yegor256/rumble) [](https://www.jetbrains.com/ruby/) [](https://github.com/yegor256/rumble/actions/workflows/rake.yml) [](http://www.0pdd.com/p?name=yegor256/rumble) [](http://badge.fury.io/rb/rumble) [](https://codeclimate.com/github/yegor256/rumble/maintainability) [](https://codecov.io/github/yegor256/rumble?branch=master)  [](https://hitsofcode.com/view/github/yegor256/0rsk) This command line tool helps you send newsletters. Install it first: ```bash $ gem install rumble ``` Run it locally and read its output: ```bash $ rumble --help ``` Simple liquid letter looks like this: ``` {{ first }}, How are you? Best, Yegor ``` The list of emails must contain three columns separated by a comma: first name, last name, and email. If you want to send via HTTP/SMTP proxy, use `--proxy=socks::`. ## How to contribute Read [these guidelines](https://www.yegor256.com/2014/04/15/github-guidelines.html). Make sure you build is green before you contribute your pull request. You will need to have [Ruby](https://www.ruby-lang.org/en/) 2.3+ and [Bundler](https://bundler.io/) installed. Then: ``` $ bundle update $ bundle exec rake ``` If it's clean and you don't see any error messages, submit your pull request.