Mailrelay gem is a simple Ruby wrapper for Mailrelay.com API. You can do a large number of operations like managing subscribers and campaigns, sending your newsletters, getting your stats data, etc.
Simply run:
gem install mailrelay
You can check the API documentation to view a list of all available functions. All functions can be called with this wrapper.
If you want to create a subscriber, simply use:
require 'rubygems'
require 'mailrelay'
# Set your account hostname and api key here
hostname = 'your_account_hostname'
api_key = 'your_api_key'
api = Mailrelay::API.new hostname, api_key
api.addSubscriber :email => '[email protected]', :name => 'Name'