如何重写Rails devise gem默认SMTP以通过API发送？

class ApiMailer < Devise::Mailer
  def confirmation_instructions(record, token, opts={})
    # 自定义邮件发送逻辑
    # 使用你喜欢的API发送邮件
  end
end

# Configure the class responsible to send e-mails.
config.mailer = 'Devise::Mailer'

# Configure the class responsible to send e-mails.
config.mailer = 'ApiMailer'

def confirmation_instructions(record, token, opts={})
  # 自定义邮件发送逻辑
  # 使用你喜欢的API发送邮件
  mail(to: record.email, subject: "确认账号")
end

config.action_mailer.delivery_method = :smtp
config.action_mailer.smtp_settings = {
  address:              'smtp.example.com',
  port:                 587,
  domain:               'example.com',
  user_name:            'your_username',
  password:             'your_password',
  authentication:       'plain',
  enable_starttls_auto: true
}