<a href="/home/email_test">test</a>

def email_test
    @user = User.last
    UserMailer.welcome_email(@user).deliver_now

    redirect_to :back
end

config.action_mailer.delivery_method = :smtp
config.action_mailer.smtp_settings = {
    address:              'smtp.gmail.com',
    port:                 587,
    domain:               'gmail.com',
    user_name:            'my_mail_id@gmail.com',
    password:             'my_mail_password',
    authentication:       :plain,
    enable_starttls_auto: true
}

class UserMailer < ApplicationMailer
    default from: "my_mail_id@gmail.com"

    def welcome_email(user)
        @user = user
        mail(to: @user.email, subject: 'Welcome to My Awesome Site')
    end
end

Started GET "/home/email_test" for 121.140.234.142 at 2017-04-06 04:17:09 +0000
Cannot render console from 121.140.234.142! Allowed networks: 127.0.0.1, ::1, 127.0.0.0/127.255.255.255
Processing by HomeController#email_test as HTML
  User Load (0.2ms)  SELECT  "users".* FROM "users" WHERE "users"."inactive" = 'f' AND "users"."id" = ?  ORDER BY "users"."id" ASC LIMIT 1  [["id", 1]]
  User Load (0.3ms)  SELECT  "users".* FROM "users" WHERE "users"."inactive" = 'f'  ORDER BY "users"."id" DESC LIMIT 1
  Rendered user_mailer/welcome_email.html.erb within layouts/mailer (0.1ms)
  Rendered user_mailer/welcome_email.text.erb within layouts/mailer (0.1ms)

UserMailer#welcome_email: processed outbound mail in 11.2ms

Sent mail to user_mail_id@user_mail.com (1123.5ms)
Date: Thu, 06 Apr 2017 04:17:09 +0000
From: my_mail_id@gmail.com
To: user_mail_id@user_mail.com
Message-ID: <58e5c145eb445_8eb3fc731278548409bb@~~.mail>
Subject: Welcome to My Awesome Site
Mime-Version: 1.0
Content-Type: multipart/alternative;
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Completed 500 Internal Server Error in 1150ms (ActiveRecord: 0.5ms)

RestClient::BadRequest (400 Bad Request):
  app/controllers/home_controller.rb:137:in `email_test'


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  Rendered /usr/local/rvm/gems/ruby-2.3.0/gems/actionpack-4.2.1/lib/action_dispatch/middleware/templates/rescues/_request_and_response.html.erb (1.6ms)
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