This is the best way I found:
1- Create a config/smtp_settings.example.yml file:
development:
:method: :letter_opener
:url_options:
:host: localhost
:port: 3000
production: &production
:method: :smtp
:url_options:
:host: www.the_site.com
:smtp_settings:
address: smtp.gateway.com
port: 465
user_name: someone@somewhere.com
# etc ...
staging:
<<: *production
test:
:method: :test
:url_options:
:host: test.host
Notes:
- This uses
letter_opener
as development mailer, change to your own method
- There is a
staging
environment defined as an exact copy of the production
environment, remove if you don't use staging
2- Remove config.action_mailer.delivery_method
and config.action_mailer.default_url_options
and config.action_mailer.smtp_settings
from all files under config/environments/ folder
3- Add in the file config/application.rb the following:
config.action_mailer.delivery_method = config_for(:smtp_settings)[:method]
config.action_mailer.default_url_options = config_for(:smtp_settings)[:url_options]
config.action_mailer.smtp_settings = config_for(:smtp_settings)[:smtp_settings] if config_for(:smtp_settings)[:method] == :smtp
Notes: config_for
has been introduced in the latest version of Rails (4.2.0 as per writing). If you use an older version of rails you must manually load the yml files
And the trick on top of all of that to answer your question:
Push to your repository the file config/smtp_settings.example.yml and ignore the file config/smtp_settings.yml.
Each developper of your team would have to create their own config/smtp_settings.yml by copying the file smtp_settings.example.yml and changing the host
to match their machine's IP address, so the mail send by each developer leads to their own machine.
You off course requires you to start the local development server binded to 0.0.0.0 so it's accessible from other hosts (considering your security environment off course)