Rails SMTP

Configure Action Mailer to deliver through eusend over SMTP — mailers, Devise emails, and any deliver_now/deliver_later, DKIM-signed and tracked.

Action Mailer uses SMTP for delivery, so pointing Ruby on Rails at eusend is a one-block configuration change. Every mailer, plus Devise confirmation and password-reset emails, then routes through eusend, DKIM-signed and tracked.

config/environments/production.rb

config.action_mailer.delivery_method = :smtp
config.action_mailer.smtp_settings = {
  address:        'smtp.eusend.dev',
  port:           465,
  user_name:      'eusend',                    # the literal string "eusend"
  password:       ENV['EUSEND_API_KEY'],       # eu_live_…
  authentication: :plain,
  tls:            true,                          # implicit TLS on 465
  enable_starttls_auto: false
}

# Must be an address on a domain verified in eusend
config.action_mailer.default_options = { from: 'Acme <[email protected]>' }

⚠

Use tls: true (implicit TLS on port 465), not enable_starttls_auto. On some Ruby/net-smtp versions the option is ssl: true — both select implicit TLS.

Send an email

class OrderMailer < ApplicationMailer
  def shipped(order)
    mail(to: order.email, subject: 'Your order has shipped')
  end
end

OrderMailer.shipped(order).deliver_now   # or deliver_later

Test the connection from the Rails console:

ActionMailer::Base.mail(
  from: '[email protected]',
  to:   '[email protected]',
  subject: 'SMTP test',
  body: 'Hello from eusend.'
).deliver_now

Connection reference

Setting	Value
`address`	`smtp.eusend.dev`
`port`	`465` (or `2465`)
`tls`	`true`
`user_name`	`eusend`
`password`	your eusend API key (`eu_live_…`)
`from`	an address on a verified domain

Use an eu_test_ key in development — sends are tracked but not delivered. See the SMTP overview for limits and status codes.

config/environments/production.rb

Send an email

Connection reference

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