I wanted to preview my HTML emails without having to fill up my online email inboxes with tons of email (and then I'd have to make filters too). I also didn't want to manage actually sending real email. So, I set up my machine for local delivery. Read on for instructions.
I am running Ubuntu 9.04, however these instructions should be fine at least back to 8.04.
Step 1 - Install Postfix
sudo aptitude install postfix
During the install, choose "Local Delivery Only"
Step 2 - Configure Evolution for Receiving Locally
Open up Evolution "Applications->Internet->Evolution Mail"
Set up a new account and choose local delivery. When it asks you for a path, put in:
Note that this path may not exist if you've never received mail.
Step 3 - Configure Sanitize Email
In your rails test environment.rb put:
config.action_mailer.delivery_method = :sendmail
Then, in the initializer where you set up sanitize email:
ActionMailer::Base.sanitized_recipients = ["@"]
ActionMailer::Base.local_environments = %w( test )
If you need to know your username or hostname, just open up a terminal. The command "whoami" will give you your username, and "hostname" will give you the hostname.
Step 4 - Run your tests
Now, run your rails tests. You should have a test for every email you send, and that should trigger them to be sent locally. You may have to tell Evolution to Send/Receive. Keep in mind your tests will probably fail because they will expect email to be in test mode.
Step 5 - Set it back
Remember, when you're done previewing your email, reset config.action_mailer.delivery_method!