Ruby on Rails/ActionMailer

Note: The following documentation was taken directly from the Rails API documentation

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

Model

To use ActionMailer, you need to create a mailer model.

bin/rails 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
     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 address. These addresses will receive a blind carbon copy of your email. Sets the Bcc: 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.

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 the key points do.

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 ActionController, 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 .rhtml 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.rhtml

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.

Sending HTML Mail

To send mail as HTML, make sure your view (the .rhtml 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"
      body       "account" => recipient
      from       "system@example.com"
      content_type "text/html"   #Here's where the magic happens
    end
  end

Multipart Mail

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"

      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 ActionMailer 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.rhtml
• signup_notification.text.html.rhtml
• signup_notification.text.xml.rxml
• signup_notification.text.x-yaml.rhtml

Each would be rendered and added as a separate part to the message, with the corresponding content type. The same body hash is passed to each template.

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: 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.
• server_settings: Allows detailed configuration of the server:
  • :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
• 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. Sendmail is assumed to be present at "/usr/sbin/sendmail".
• 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 nil. You can also pick a different value from inside a method with @mime_version. When multipart messages are in use, @mime_version will be set to "1.0" if it is not set inside a method.
• 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.