exception_notification: smtp not working - smtp

Question

I am using Rails 3.2.5 and exception_notification gem. In production mode, I am generally sending emails using PostMarkApp's postmark-rails gem.
Initially, I got a View error from exception_notification gem stating
ActionView::Template::Error (code converter not found (UTF-8 to UTF-16))
so based on exception_notification gem raises ActionView::Template::Error (code converter not found (UTF-8 to UTF-16)) only on Heroku production mode, I moved to
gem 'exception_notification', git: 'git://github.com/alanjds/exception_notification.git'
This solved that bug. Now, I want the gem to send emails from my gmail account instead of using PostMarkApp credits, so I added the following to my production.rb, yet Exception Notification attempts to send email only from Post Mark App. Why is this setting not working?
config.middleware.use ExceptionNotifier,
sender_address: 'noreply#mydomain.com',
exception_recipients: 'myemail#mydomain.com',
sections: %w{current_user} + ExceptionNotifier::Notifier.default_sections,
ignore_crawlers: %w{Googlebot bingbot},
email_format: true,
normalize_subject: true,
smtp_settings: {
:address => "smtp.gmail.com",
:port => "587",
:domain => "www.gmail.com",
:user_name => "myemail#gmail.com",
:password => "mypassword",
:authentication => "plain",
:enable_starttls_auto => true,
:openssl_verify_mode => 'none'
}
config.action_mailer.delivery_method = :postmark
config.action_mailer.postmark_settings = { :api_key => "_____" }

Answer 1

For some reason it appears that SMTP delivery does NOT work in the development environment. I tried a number of different settings and was never able to get this to work. It DOES however work in my other environments. Older posts seem to indicate this as well:
http://www.ruby-forum.com/topic/64776
http://www.devchix.com/2008/12/09/how-to-see-exception_notification-plugin-work-in-development-mode/
In development, I am using the following in my development.rb:
config.action_mailer.delivery_method = :letter_opener
config.middleware.use ExceptionNotifier,
:sender_address => 'test#test.com',
:exception_recipients => 'recipient#test.com'
In my "staging" environment, I am using the following in my staging.rb:
config.action_mailer.delivery_method = :smtp
config.middleware.use ExceptionNotifier,
:sender_address => 'test#test.com',
:exception_recipients => 'recipient#test.com'
The staging.rb acquires it's SMTP settings from an initializer I have the uses SendGrid for SMTP:
ActionMailer::Base.smtp_settings = {
:address => "smtp.sendgrid.net",
:port => 25,
:domain => "test.com",
:user_name => "user_name",
:password => "password",
:authentication => "plain"
}

Answer 2

Try the suggestion at http://www.scottw.com/multiple-smtp-servers-with-action-mailer
or at Rails ActionMailer with multiple SMTP servers