Action Mailer allows you to send email from your application using a mailer model and views.

Mailer Models

To use Action Mailer, you need to create a mailer model.

  $ script/generate mailer Notifier

The generated model inherits from ActionMailer::Base. Emails are defined by creating methods within the model which are then used to set variables to be used in the mail template, to change options on the mail, or to add attachments.

Examples:

 class Notifier < ActionMailer::Base
   def signup_notification(recipient)
     recipients recipient.email_address_with_name
     bcc        ["bcc@example.com", "Order Watcher <watcher@example.com>"]
     from       "system@example.com"
     subject    "New account information"
     body       :account => recipient
   end
 end

Mailer methods have the following configuration methods available.

• recipients - Takes one or more email addresses. These addresses are where your email will be delivered to. Sets the To: header.
• subject - The subject of your email. Sets the Subject: header.
• from - Who the email you are sending is from. Sets the From: header.
• cc - Takes one or more email addresses. These addresses will receive a carbon copy of your email. Sets the Cc: header.
• bcc - Takes one or more email addresses. These addresses will receive a blind carbon copy of your email. Sets the Bcc: header.
• reply_to - Takes one or more email addresses. These addresses will be listed as the default recipients when replying to your email. Sets the Reply-To: header.
• sent_on - The date on which the message was sent. If not set, the header wil be set by the delivery agent.
• content_type - Specify the content type of the message. Defaults to text/plain.
• headers - Specify additional headers to be set for the message, e.g. headers ‘X-Mail-Count’ => 107370.

When a headers ‘return-path‘ is specified, that value will be used as the ‘envelope from’ address. Setting this is useful when you want delivery notifications sent to a different address than the one in from.

The body method has special behavior. It takes a hash which generates an instance variable named after each key in the hash containing the value that that key points to.

So, for example, body :account => recipient would result in an instance variable @account with the value of recipient being accessible in the view.

Mailer views

Like Action Controller, each mailer class has a corresponding view directory in which each method of the class looks for a template with its name. To define a template to be used with a mailing, create an .erb file with the same name as the method in your mailer model. For example, in the mailer defined above, the template at app/views/notifier/signup_notification.erb would be used to generate the email.

Variables defined in the model are accessible as instance variables in the view.

Emails by default are sent in plain text, so a sample view for our model example might look like this:

  Hi <%= @account.name %>,
  Thanks for joining our service! Please check back often.

You can even use Action Pack helpers in these views. For example:

  You got a new note!
  <%= truncate(note.body, 25) %>

Generating URLs

URLs can be generated in mailer views using url_for or named routes. Unlike controllers from Action Pack, the mailer instance doesn‘t have any context about the incoming request, so you‘ll need to provide all of the details needed to generate a URL.

When using url_for you‘ll need to provide the :host, :controller, and :action:

  <%= url_for(:host => "example.com", :controller => "welcome", :action => "greeting") %>

When using named routes you only need to supply the :host:

  <%= users_url(:host => "example.com") %>

You will want to avoid using the name_of_route_path form of named routes because it doesn‘t make sense to generate relative URLs in email messages.

It is also possible to set a default host that will be used in all mailers by setting the :host option in the ActionMailer::Base.default_url_options hash as follows:

  ActionMailer::Base.default_url_options[:host] = "example.com"

This can also be set as a configuration option in config/environment.rb:

  config.action_mailer.default_url_options = { :host => "example.com" }

If you do decide to set a default :host for your mailers you will want to use the :only_path => false option when using url_for. This will ensure that absolute URLs are generated because the url_for view helper will, by default, generate relative URLs when a :host option isn‘t explicitly provided.

Sending mail

Once a mailer action and template are defined, you can deliver your message or create it and save it for delivery later:

  Notifier.deliver_signup_notification(david) # sends the email
  mail = Notifier.create_signup_notification(david)  # => a tmail object
  Notifier.deliver(mail)

You never instantiate your mailer class. Rather, your delivery instance methods are automatically wrapped in class methods that start with the word deliver_ followed by the name of the mailer method that you would like to deliver. The signup_notification method defined above is delivered by invoking Notifier.deliver_signup_notification.

HTML email

To send mail as HTML, make sure your view (the .erb file) generates HTML and set the content type to html.

  class MyMailer < ActionMailer::Base
    def signup_notification(recipient)
      recipients   recipient.email_address_with_name
      subject      "New account information"
      from         "system@example.com"
      body         :account => recipient
      content_type "text/html"
    end
  end

Multipart email

You can explicitly specify multipart messages:

  class ApplicationMailer < ActionMailer::Base
    def signup_notification(recipient)
      recipients      recipient.email_address_with_name
      subject         "New account information"
      from            "system@example.com"
      content_type    "multipart/alternative"

      part :content_type => "text/html",
        :body => render_message("signup-as-html", :account => recipient)

      part "text/plain" do |p|
        p.body = render_message("signup-as-plain", :account => recipient)
        p.transfer_encoding = "base64"
      end
    end
  end

Multipart messages can also be used implicitly because Action Mailer will automatically detect and use multipart templates, where each template is named after the name of the action, followed by the content type. Each such detected template will be added as separate part to the message.

For example, if the following templates existed:

• signup_notification.text.plain.erb
• signup_notification.text.html.erb
• signup_notification.text.xml.builder
• signup_notification.text.x-yaml.erb

Each would be rendered and added as a separate part to the message, with the corresponding content type. The content type for the entire message is automatically set to multipart/alternative, which indicates that the email contains multiple different representations of the same email body. The same body hash is passed to each template.

Implicit template rendering is not performed if any attachments or parts have been added to the email. This means that you‘ll have to manually add each part to the email and set the content type of the email to multipart/alternative.

Attachments

Attachments can be added by using the attachment method.

Example:

  class ApplicationMailer < ActionMailer::Base
    # attachments
    def signup_notification(recipient)
      recipients      recipient.email_address_with_name
      subject         "New account information"
      from            "system@example.com"

      attachment :content_type => "image/jpeg",
        :body => File.read("an-image.jpg")

      attachment "application/pdf" do |a|
        a.body = generate_your_pdf_here()
      end
    end
  end

Configuration options

These options are specified on the class level, like ActionMailer::Base.template_root = "/my/templates"

• template_root - Determines the base from which template references will be made.
• logger - the logger is used for generating information on the mailing run if available. Can be set to nil for no logging. Compatible with both Ruby‘s own Logger and Log4r loggers.
• smtp_settings - Allows detailed configuration for :smtp delivery method:
  • :address - Allows you to use a remote mail server. Just change it from its default "localhost" setting.
  • :port - On the off chance that your mail server doesn‘t run on port 25, you can change it.
  • :domain - If you need to specify a HELO domain, you can do it here.
  • :user_name - If your mail server requires authentication, set the username in this setting.
  • :password - If your mail server requires authentication, set the password in this setting.
  • :authentication - If your mail server requires authentication, you need to specify the authentication type here. This is a symbol and one of :plain, :login, :cram_md5.
  • :enable_starttls_auto - When set to true, detects if STARTTLS is enabled in your SMTP server and starts to use it. It works only on Ruby >= 1.8.7 and Ruby >= 1.9. Default is true.
• sendmail_settings - Allows you to override options for the :sendmail delivery method.
  • :location - The location of the sendmail executable. Defaults to /usr/sbin/sendmail.
  • :arguments - The command line arguments. Defaults to -i -t.
• raise_delivery_errors - Whether or not errors should be raised if the email fails to be delivered.
• delivery_method - Defines a delivery method. Possible values are :smtp (default), :sendmail, and :test.
• perform_deliveries - Determines whether deliver_* methods are actually carried out. By default they are, but this can be turned off to help functional testing.
• deliveries - Keeps an array of all the emails sent out through the Action Mailer with delivery_method :test. Most useful for unit and functional testing.
• default_charset - The default charset used for the body and to encode the subject. Defaults to UTF-8. You can also pick a different charset from inside a method with charset.
• default_content_type - The default content type used for the main part of the message. Defaults to "text/plain". You can also pick a different content type from inside a method with content_type.
• default_mime_version - The default mime version used for the message. Defaults to 1.0. You can also pick a different value from inside a method with mime_version.
• default_implicit_parts_order - When a message is built implicitly (i.e. multiple parts are assembled from templates which specify the content type in their filenames) this variable controls how the parts are ordered. Defaults to ["text/html", "text/enriched", "text/plain"]. Items that appear first in the array have higher priority in the mail client and appear last in the mime encoded message. You can also pick a different order from inside a method with implicit_parts_order.