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This README follows master, which may not be the currently published version! Use the docs for the published version of Bamboo.

Bamboo is part of the thoughtbot Elixir family of projects.

Flexible and easy to use email for Elixir.

  • Adapter based so it can be used with Mandrill, SMTP, or whatever else you want. Comes with a Mandrill adapter out of the box.
  • Deliver emails in the background. Most of the time you don’t want or need to wait for the email to send. Bamboo makes it easy with Mailer.deliver_later
  • Easy to format recipients. You can do new_email(to: and Bamboo can format the User struct if you implement Bamboo.Formatter.
  • Works out of the box with Phoenix. Use views and layouts to make rendering email easy.
  • Very composable. Emails are just a Bamboo.Email struct and can be manipulated with plain functions.
  • Easy to unit test. Because delivery is separated from email creation, no special functions are needed, just assert against fields on the email.
  • Easy to test delivery in integration tests. Helpers are provided to make testing easy and robust.
  • View sent emails during development. Bamboo comes with a plug that can be used in your router to view sent emails.

See the docs for the most up to date information.

We designed Bamboo to be simple and powerful. If you run into anything that is less than exceptional, or you just need some help, please open an issue.


The Bamboo.MandrillAdapter and Bamboo.SendGridAdapter are being used in production and have had no issues. It’s also pretty simple to create your own adapter. Feel free to open an issue or a PR if you’d like to add a new adapter to the list.

To switch adapters, change the config for your mailer:

# In your config file
config :my_app, MyApp.Mailer,
  adapter: Bamboo.LocalAdapter


  1. Add bamboo to your list of dependencies in mix.exs:
def deps do
  # Get from hex
  [{:bamboo, "~> 1.2"}]
  # Or use the latest from master
  [{:bamboo, github: "thoughtbot/bamboo"}]
  1. Ensure bamboo is started before your application:
def application do
  [applications: [:bamboo]]

Getting Started

Do you like to learn by watching? Check out the free Bamboo screencast from DailyDrip.

It is a wonderful introduction to sending and testing emails with Bamboo. It also covers some of the ways that Bamboo helps catch errors, how some of the internals work, and how to format recipients with the Bamboo.Formatter protocol.

Bamboo breaks email creation and email sending into two separate modules. This is done to make testing easier and to make emails easy to pipe/compose.

# In your config/config.exs file
# There may be other adapter specific configuration you need to add.
# Be sure to check the adapter's docs. For example, Mailgun requires a `domain` key.
config :my_app, MyApp.Mailer,
  adapter: Bamboo.MandrillAdapter,
  api_key: "my_api_key"

# Somewhere in your application
defmodule MyApp.Mailer do
  use Bamboo.Mailer, otp_app: :my_app

# Define your emails
defmodule MyApp.Email do
  import Bamboo.Email

  def welcome_email do
      to: "",
      from: "",
      subject: "Welcome to the app.",
      html_body: "<strong>Thanks for joining!</strong>",
      text_body: "Thanks for joining!"

    # or pipe using Bamboo.Email functions
    |> to("")
    |> from("")
    |> subject("Welcome!!!")
    |> html_body("<strong>Welcome</strong>")
    |> text_body("welcome")

# In a controller or some other module
Email.welcome_email |> Mailer.deliver_now

# You can also deliver emails in the background with Mailer.deliver_later
Email.welcome_email |> Mailer.deliver_later

Delivering Emails in the Background

Often times you don’t want to send email right away because it will slow down things like web requests in Phoenix. Bamboo offers deliver_later on your mailers to send emails in the background so that your requests don’t block.

By default delivering later uses Bamboo.TaskSupervisorStrategy. This strategy sends the email right away, but does so in the background without linking to the calling process, so errors in the mailer won’t bring down your app.

If you need something more custom you can create a strategy with Bamboo.DeliverLaterStrategy. For example, you could create strategies for adding emails to a background processing queue such as exq or toniq.

Composing with Pipes (for default from address, default layouts, etc.)

defmodule MyApp.Email do
  import Bamboo.Email
  import Bamboo.Phoenix

  def welcome_email do
    |> to("")
    |> subject("Welcome!!!")
    |> put_header("Reply-To", "")
    |> html_body("<strong>Welcome</strong>")
    |> text_body("Welcome")

  defp base_email do
    # Here you can set a default from, default headers, etc.
    |> from("")
    |> put_html_layout({MyApp.LayoutView, "email.html"})
    |> put_text_layout({MyApp.LayoutView, "email.text"})

Handling Recipients

The from, to, cc and bcc addresses can be passed a string, or a 2 item tuple.

Sometimes doing this can be a pain though. What happens if you try to send to a list of users? You’d have to do something like this for every email:

# This stinks. Do you want to do this every time you create a new email?
users = for user <- users do

new_email(to: users)

To circumvent this, Bamboo has a Bamboo.Formatter protocol. See the Bamboo.Email and Bamboo.Formatter docs for more info and examples.

Using Phoenix Views and Layouts

Phoenix is not required to use Bamboo. However, if you do use Phoenix, you can use Phoenix views and layouts with Bamboo. See Bamboo.Phoenix

Viewing Sent Emails

Bamboo comes with a handy plug for viewing emails sent in development. Now you don’t have to look at the logs to get password resets, confirmation links, etc. Just open up the sent email viewer and click the link.

See Bamboo.SentEmailViewerPlug

Here is what it looks like:

Screenshot of BambooSentEmailViewer

Mandrill Specific Functionality (tags, merge vars, templates, etc.)

Mandrill offers extra features on top of regular SMTP email like tagging, merge vars, templates, and scheduling emails to send in the future. See Bamboo.MandrillHelper.

SendGrid Specific Functionality (templates and substitution tags)

SendGrid offers extra features on top of regular SMTP email like transactional templates with substitution tags. See Bamboo.SendGridHelper.

JSON support

Bamboo comes with JSON support out of the box via the Poison library. To use it, add :poison to your dependencies:

{:poison, ">= 1.5.0"}

You can customize it to use another library via the :json_library configuration:

config :bamboo, :json_library, SomeOtherLib


You can use the Bamboo.TestAdapter along with Bamboo.Test to make testing your emails straightforward.

# Using the mailer from the Getting Started section
defmodule MyApp.Registration do
  use ExUnit.Case
  use Bamboo.Test

  test "welcome email" do
    # Unit testing is easy since the email is just a struct
    user = new_user

    email = Email.welcome_email(user)

    assert == user
    # The =~ checks that the html_body contains the text on the right
    assert email.html_body =~ "Thanks for joining"

  test "after registering, the user gets a welcome email" do
    # Integration test with the helpers from Bamboo.Test
    user = new_user


    assert_delivered_email MyApp.Email.welcome_email(user)

See documentation for Bamboo.Test for more examples, and remember to use Bamboo.TestAdapter.

About thoughtbot


Bamboo is maintained and funded by thoughtbot, inc. The names and logos for thoughtbot are trademarks of thoughtbot, inc.

We love open source software, Elixir, and Phoenix. See our other Elixir projects, or hire our Elixir Phoenix development team to design, develop, and grow your product.


Before opening a pull request, please open an issue first.

Once we’ve decided how to move forward with a pull request:

$ git clone
$ cd bamboo
$ mix deps.get
$ mix test

Once you’ve made your additions and mix test passes, go ahead and open a PR!


Thanks to @mtwilliams for an early version of the SendGridAdapter.