Ruby on Rails

class UserMailer < ApplicationMailer

  default from: "GMAIL_ACCOUNT"

  def send_mail_agent(user)

    @user = user

    mail :to => user.email, :subject => "your ticket in process"

  end

  def receive(email)

    page = Page.find_by(address: email.to.first)

    page.emails.create(

        subject: email.subject,

        body: email.body

    )

    if email.has_attachments?

      email.attachments.each do |attachment|

        page.attachments.create({

                                    file: attachment,

                                    description: email.subject

                                })

      end

    end

  end

end

    address:        'smtp.gmail.com', # default: localhost
    port:           '25',                  # default: 25
    user_name:      'GAMIL_ACCOUNT',
    password:       'GMAIL_PASSWORD',
    authentication: :plain                 # :plain, :login or :cram_md5
 }

I tried to run the command rails runner 'UserMailer.receive(STDIN.read)'

But nothing happened even the email is incoming .It does not call the receive method
Where should i call the receive method ??? How determine the incoming email ???