Connecting Rails to Microsoft Exchange / SMTP Email Server

17 April 2013 by Jess Brown

When a client first asked me to switch from Sendgrid to use their smtp exchange server, I figured it'd be really simple...like connecting to a gmail account. However, I ran into a few issues. Like a lot in programming, it wasn't anything way different than what I was doing, but a couple to syntax differences. Hopefully, someone will find find this helpful (surprisingly google didn't help me much with my searches).

So, here's the standard gmail setup:

config.action_mailer.delivery_method = :smtp
config.action_mailer.smtp_settings = {
  :address        => 'smtp.gmail.com',
    :port           => '587',
    :authentication => :plan,
    :user_name      => ENV['SMTP_USERNAME'],
    :password       => ENV['SMTP_PASSWORD'],
    :domain         => 'brownwebdesign.com',
    :enable_starttls_auto => true
}

Just a few small changes below to the authentication type.

config.action_mailer.delivery_method = :smtp
config.action_mailer.smtp_settings = {
  :address        => 'smtp.office365.com',
    :port           => '587',
    :authentication => :login,
    :user_name      => ENV['SMTP_USERNAME'],
    :password       => ENV['SMTP_PASSWORD'],
    :domain         => 'congrueit.com',
    :enable_starttls_auto => true
}

Your SMTP_USERNAME should be your whole email address.

The other thing that got me was you need to send from the actual account you're using to log in with. For example, don't send email from noreply@brownwebdesign.com and use support@brownwebdesign.com as your SMTP_USERNAME.

There may be some other setting on the exchange side that needs to be tweaked (smtp allowed, authentication, etc.), but I think my client had

Debugging

Maybe the more interesting this is how to debug it.

The app isn't in production yet, but I tried it on the production server first; didn't work. So, easy way never works. Try in test/dev first I use mailcatcher.me in development mode, so I took the smtp settings (above) from config/environments/production.rb and placed them in config/environments/development.rb

Then I made sure that config.action_mailer.raise_delivery_errors = false was set to true and that helped debug the reasons things were going wrong. I got an error about wrong authentication type and then that my account didn't have permission to send (was using different from address).