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
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.
- 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.