ActionMailer: Default From: address?

Rails 3

config/environments/development.rb:

ActionMailer::Base.default :from => '[email protected]'

config/environments/production.rb:

ActionMailer::Base.default :from => '[email protected]'

You can also set this per mailer:

class MyMailer < ActionMailer::Base
  default :from => '[email protected]'
end

Rails 2

This is not supported by default. But you can achieve this functionality by using the action_mailer_callbacks plugin. Essentially this plugin allows you to add before and after filters for the deliver method.

class FooMailer < ActionMailer::Base
  before_deliver do |mail|
    mail.from = "[email protected]"
  end

end

Reference:

1) Article discussing the plugin.

OR

You can monkey patch the from method of ActionMailer::Base.

Add the code below to your config\initializers\mail.rb

class ActionMailer::Base
  class_inheritable_hash :default
  def from_with_default(input=nil)
    return from_without_default(input) || default[:from] if input.nil?
    from_without_default(input)
  end
  alias_method_chain :from, :default
end

Now you can configure your default value as follows:

config/environments/development.rb:

ActionMailer::Base.default = {:from => '[email protected]'}

config/environments/production.rb:

ActionMailer::Base.default = {:from => '[email protected]'}

You can also set this per mailer:

class MyMailer < ActionMailer::Base
  self.default = {:from => '[email protected]'}
end

In Rails 4 you can set this in your environment(s):

config.action_mailer.default_options = {
  :from => "[email protected]"
}