Sendgrid set up on Rails 4 - ruby-on-rails

Question

I have a rails 4 app. I set up ActionMailer and I can send order confirmation emails via localhost and gmail.
I installed Sendgrid on Heroku and followed the set up instructions. I get a Net::SMTPSyntaxError (501 Syntax error
my environment.rb (i have sendgrid user/pwd in application.yml)
ActionMailer::Base.smtp_settings = {
:address => 'smtp.sendgrid.net',
:port => '587',
:authentication => :plain,
:user_name => ENV['SENDGRID_USERNAME'],
:password => ENV['SENDGRID_PASSWORD'],
:domain => 'heroku.com',
:enable_starttls_auto => true
}
in production.rb - the only actionamailer setting i have is this. I have this as a placeholder to put the real domain in later. I'm currently using herokuapp.com.
config.action_mailer.default_url_options = { host: 'localhost:3000' }
in my orders_controller within the order create method, I call the below.
AutoNotifier.orderconf_email(current_user, #order).deliver
auto_notifier.rb
class AutoNotifier < ActionMailer::Base
default from: "Test Email"
def orderconf_email(current_user, order)
#buyer = current_user
#order = order
mail(to: #buyer.email, subject: 'Thank you for your order.')
end
end
What am I missing? It works on localhost with gmail so I'm missing something in the sendgrid settings or in the default_url in production.rb file.

Answer 1

For posterity, here's a working setup for external SMTP in Rails on Heroku:
#config/environments/production.rb
config.action_mailer.smtp_settings = {
:address => "smtp.sendgrid.net",
:port => 587, # ports 587 and 2525 are also supported with STARTTLS
:enable_starttls_auto => true, # detects and uses STARTTLS
:user_name => ENV["SENDGRID_USERNAME"],
:password => ENV["SENDGRID_PASSWORD"], # SMTP password is any valid API key, when user_name is "apikey".
:authentication => 'login',
:domain => 'yourdomain.com', # your domain to identify your server when connecting
}

Answer 2

Change default from: "Test Email" to valid email address, even example#example.com.

Answer 3

I would just like to point out, this is for sending emails via SMTP. While this method is totally ok, you should also consider sending via the API.
To do this, you need to specify an interceptor. Luckily, there's a Gem that helps with that. Here's a good article showing how to use it.
https://rubyplus.com/articles/561-Sending-Emails-using-SendGrid-API-in-Rails-4-1

Answer 4

It took us a long time to resolve the issue when we tried to deploy the SMTP relay on heroku. It worked perfectly fine on local but when pushed we received socket errors and time out issues. Eventually got it working.
Important note: Make sure not to use starttls_auto and SSL/or TLS this causes open SSL issue.