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Version: 0.7

Create emailing backends

Marten lets you easily create custom emailing backends that you can then use as part of your application when it comes to sending emails.

Basic backend definition​

Defining an emailing backend is as simple as creating a class that inherits from the Marten::Emailing::Backend::Base abstract class and that implements a unique #deliver method. This method takes a single email argument (instance of Marten::Emailing::Email), corresponding to the email to deliver.

For example:

class CustomEmailingBackend < Marten::Emailing::Backend::Base
  def deliver(email : Email)
    # Deliver the email!
  end
end

Handling attachments​

If your backend supports attachments, you can iterate over #attachments in the #deliver implementation:

class CustomEmailingBackend < Marten::Emailing::Backend::Base
  def deliver(email : Email)
    email.attachments.each do |attachment|
      # attachment.filename
      # attachment.mime_type
      # attachment.content
    end
  end
end

Each attachment exposes:

  • a filename
  • a mime_type
  • a content byte slice
  • a size in bytes

Enabling the use of custom emailing backends​

Custom emailing backends can be used by assigning an instance of the corresponding class to the emailing.backend setting.

For example:

config.emailing.backend = CustomEmailingBackend.new