campaign is a comprehensive solution for sending emails in Node, and it comes with a very simple API.
You instance it like this.
var client = require('campaign')({
from: '[email protected]'
});
To send emails, you can use Mandrill, which is free and awesome. Just set your API key, like this:
process.env.MANDRILL_APIKEY = '<your api key>';
(if you want to send emails using another provider, check the docs)
Then, when you want to send an email, you can do it like this:
client.sendString('<p>{{something}}</p>', {
to: ['[email protected]', '[email protected]'],
subject: 'Some Subject',
preview': 'The first line',
something: 'this is what replaces that thing in the template'
}, done);
The GitHub repo has pretty extensive documentation.