Skip to content
Mail for Ruby applications
Ruby Other
  1. Ruby 98.3%
  2. Other 1.7%
Branch: master
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Type Name Latest commit message Commit time
Failed to load latest commit information.
.circleci Ruby 2.6 (#76) Jan 7, 2019
lib Prepare for v1.3.1 Jan 15, 2019
script Code quality tools (#74) Jul 24, 2018
spec Prepare for v1.3.1 Jan 15, 2019
.gitignore Remove accidentally committed files. Oct 3, 2017
.jrubyrc Code quality tools (#74) Jul 24, 2018
.rspec Migrate from Minitest to RSpec (#67) Mar 23, 2017
.travis.yml CHANGELOG [ci skip] Jan 18, 2019
Gemfile Prepare for v1.3.0 Oct 23, 2018 Update copyright to 2017 [ci skip] Mar 6, 2017 Code quality tools (#74) Jul 24, 2018
hanami-mailer.gemspec Prepare for v1.3.1 Jan 15, 2019


Mail for Ruby applications.


Gem Version TravisCI CircleCI Test Coverage Depfu Inline Docs



Hanami::Mailer supports Ruby (MRI) 2.3+ and JRuby


Add this line to your application's Gemfile:

gem 'hanami-mailer'

And then execute:

$ bundle

Or install it yourself as:

$ gem install hanami-mailer



  • Templates are searched under Hanami::Mailer.configuration.root, set this value according to your app structure (eg. "app/templates").
  • A mailer will look for a template with a file name that is composed by its full class name (eg. "articles/index").
  • A template must have two concatenated extensions: one for the format and one for the engine (eg. ".html.erb").
  • The framework must be loaded before rendering the first time: Hanami::Mailer.load!.


A simple mailer looks like this:

require 'hanami/mailer'

class InvoiceMailer
  include Hanami::Mailer

A mailer with .to and .from addresses and mailer delivery:

require 'hanami/mailer'

Hanami::Mailer.configure do
  delivery_method :smtp,
    address:              "",
    port:                 587,
    domain:               "",
    user_name:            ENV['SMTP_USERNAME'],
    password:             ENV['SMTP_PASSWORD'],
    authentication:       "plain",
    enable_starttls_auto: true

class WelcomeMailer
  include Hanami::Mailer

  from ''
  to   ''
  cc   ''
  bcc  ''

  subject 'Welcome'



The set of objects passed in the deliver call are called locals and are available inside the mailer and the template.

require 'hanami/mailer'

User =, :username, :email)
luca ='Luca', 'jodosha', '')

class WelcomeMailer
  include Hanami::Mailer

  from    ''
  subject 'Welcome'
  to      :recipient


  def recipient

WelcomeMailer.deliver(user: luca)

The corresponding erb file:

Hello <%= %>!


All public methods defined in the mailer are accessible from the template:

require 'hanami/mailer'

class WelcomeMailer
  include Hanami::Mailer

  from    ''
  to      ''
  subject 'Welcome'

  def greeting
<h2><%= greeting %></h2>


The template file must be located under the relevant root and must match the inflected snake case of the mailer class name.

# Given this root
Hanami::Mailer.configuration.root      # => #<Pathname:app/templates>

# For InvoiceMailer, it looks for:
#  * app/templates/invoice_mailer.html.erb
#  * app/templates/invoice_mailer.txt.erb

If we want to specify a different template, we can do:

class InvoiceMailer
  include Hanami::Mailer

  template 'invoice'

# It will look for:
#  * app/templates/invoice.html.erb
#  * app/templates/invoice.txt.erb


The builtin rendering engine is ERb.

This is the list of the supported engines. They are listed in order of higher precedence, for a given extension. For instance, if ERubis is loaded, it will be preferred over ERb to render .erb templates.

Engine Extensions
Erubis erb, rhtml, erubis
ERb erb, rhtml
Redcarpet markdown, mkd, md
RDiscount markdown, mkd, md
Kramdown markdown, mkd, md
Maruku markdown, mkd, md
BlueCloth markdown, mkd, md
Asciidoctor ad, adoc, asciidoc
Builder builder
CSV rcsv
CoffeeScript coffee
WikiCloth wiki, mediawiki, mw
Creole wiki, creole
Etanni etn, etanni
Haml haml
Less less
Liquid liquid
Markaby mab
Nokogiri nokogiri
Plain html
RDoc rdoc
Radius radius
RedCloth textile
Sass sass
Scss scss
Slim slim
String str
Yajl yajl


Hanami::Mailer can be configured with a DSL that determines its behavior. It supports a few options:

require 'hanami/mailer'

Hanami::Mailer.configure do
  # Set the root path where to search for templates
  # Argument: String, Pathname, #to_pathname, defaults to the current directory
  root '/path/to/root'

  # Set the default charset for emails
  # Argument: String, defaults to "UTF-8"
  default_charset 'iso-8859'

  # Set the delivery method
  # Argument: Symbol
  # Argument: Hash, optional configurations
  delivery_method :stmp


Attachments can be added with the following API:

class InvoiceMailer
  include Hanami::Mailer
  # ...

  def prepare
    mail.attachments['invoice.pdf'] = '/path/to/invoice.pdf'
    # or
    mail.attachments['invoice.pdf'] ='/path/to/invoice.pdf')

Delivery Method

The global delivery method is defined through the Hanami::Mailer configuration, as:

Hanami::Mailer.configuration do
  delivery_method :smtp
Hanami::Mailer.configuration do
  delivery_method :smtp, address: "localhost", port: 1025

Builtin options are:

  • Exim (:exim)
  • Sendmail (:sendmail)
  • SMTP (:smtp, for local installations)
  • SMTP Connection (:smtp_connection, via Net::SMTP - for remote installations)
  • Test (:test, for testing purposes)

Custom Delivery Method

Developers can specify their own custom delivery policy:

require 'hanami/mailer'

class MandrillDeliveryMethod
  def initialize(options)
    @options = options

  def deliver!(mail)
    # ...

Hanami::Mailer.configure do
  delivery_method MandrillDeliveryMethod,
    username: ENV['MANDRILL_USERNAME'],
    password: ENV['MANDRILL_API_KEY']

The class passed to .delivery_method must accept an optional set of options with the constructor (#initialize) and respond to #deliver!.

Multipart Delivery

All the email are sent as multipart messages by default. For a given mailer, the framework looks up for associated text (.txt) and HTML (.html) templates and render them.

InvoiceMailer.deliver               # delivers both text and html templates
InvoiceMailer.deliver(format: :txt) # delivers only text template

Please note that they aren't both mandatory, but at least one of them MUST be present.


Hanami::Mailer uses Semantic Versioning 2.0.0


Copyright © 2015-2017 Luca Guidi – Released under MIT License

This project was formerly known as Lotus (lotus-mailer).

You can’t perform that action at this time.