[ACCEPTED]-Heroku/devise - Missing host to link to! Please provide :host parameter or set default_url_options[:host]-actionmailer

You need to add this to your environment.rb

  config.action_mailer.default_url_options = { :host => 'localhost' }

Make sure you 10 change host to your production url and keep 9 it localhost for development. This is for 8 the mailer, it needs a default email to 7 send out notices such as confirmations etc...

You 6 should check the logs on the heroku server 5 heroku logs run that from the console and it will tell 4 you the exact error.

When you push to heroku 3 you need to configure the environment.rb file with the 2 heroku subdomain:

config.action_mailer.default_url_options = { :host => 'yourapp.heroku.com' }

Depending upon version, this 1 should go in production.rb, not environment.rb.

Ok,

First you have to install the sendgrid 4 gem with this command line:

heroku addons:add sendgrid:free

Then you just 3 have to configure your env/dev.rb and env/prod.rb 2 like this:

env/dev.rb

config.action_mailer.default_url_options = { :host => 'localhost:3000' }

env/prod.rb

config.action_mailer.default_url_options = { :host => 'yourapp.heroku.com' }

Push on git 1 and heroku. It should work..

Codeglot's anwser above does the job, but 7 we wanted something a bit more flexible, so 6 we did this:

On Heroku, we run multiple Production 5 environments for staging and testing, so 4 we need a flexible solution for the production.rb 3 environment file.

In production.rb

config.action_mailer.default_url_options = { :host => ENV['MAILER_URL'] }

Then set 2 the MAILER_URL environment variable for 1 your app like so

heroku config:set MAILER_URL=my-awesome-app.herokuapp.com --app my-awesome-app

If you're running on Cedar:

1. run heroku addons:add sendgrid:free from your console.

2. Add the following 1 lines to config/environments/production.rb in your app.

.

  ActionMailer::Base.smtp_settings = {
    :address        => 'smtp.sendgrid.net',
    :port           => '587',
    :authentication => :plain,
    :user_name      => ENV['SENDGRID_USERNAME'],
    :password       => ENV['SENDGRID_PASSWORD'],
    :domain         => 'heroku.com'
  }

  ActionMailer::Base.delivery_method = :smtp

  config.action_mailer.default_url_options = { :host => 'YOUR-DOMAIN-HERE.COM' }

I had to do a number of things to get it 3 to work in the production environment: Inside of 2 my production.rb file (/config/environments/production.rb) I 1 added the following:

Rails.application.routes.default_url_options[:host] = 'myappsname.herokuapp.com'
config.action_mailer.delivery_method = :smtp
config.action_mailer.perform_deliveries = true
config.action_mailer.raise_delivery_errors = false
config.action_mailer.default :charset => "utf-8"

This is with Rails 4 and Devise 3

The working one after so many research,

1. Don't 4 forget to add default from: mail address in your ApplicationMailer (application_mailer.rb) as,

   class ApplicationMailer < ActionMailer::Base
     default from: 'yourmail@gmail.com'
     layout 'mailer'
   end
   

2. Add 3 the below configuration in your production.rb.

   config.action_mailer.default_url_options = 
     { :host => 'yourapp.herokuapp.com' }
   config.action_mailer.delivery_method = :smtp
   config.action_mailer.smtp_settings = {
     address:              'smtp.gmail.com',
     port:                 587,
     domain:               'heroku.com',
     user_name:            'yourmail@gmail.com',
     password:             'yourgmailpassword',
     authentication:       'login',
     enable_starttls_auto: true
   }
   

3. Enable 2 IMAP from your Gmail settings in Forwarding IMAP/POP tab.

4. Allow less secure apps: ON from 1 https://myaccount.google.com/lesssecureapps

You're now good to go. :)