app/mailers/user_mailer.rb
class UserMailer < ApplicationMailer
default from: 'postmaster@codenamecrud.ru'
def welcome_email(user)
@user = user
@url = 'http://codenamecrud.ru/'
mail(to: @user.email, subject: 'Добро пожаловать на Сodenamecrud.ru',
template_path: 'user_mailer', template_name: 'welcome_email')
end
end