mail.rb

#!/usr/bin/env ruby

require 'net/smtp'

unless (2..3).include? ARGV.length
  puts 'Usage: mail.rb SUBJECT TO [FROM]'
  exit 1
end

subject, to, from_ = ARGV

from    = from_             || ENV['FROM'] || '...'
server  = ENV['SERVER']     || 'email-smtp.eu-west-1.amazonaws.com'
user    = ENV['SMTP_USER']  || '...'
pass    = ENV['SMTP_PASS']  || '...'
message = $stdin.read

mail    = <<EOF
From: #{from}
To: #{to}
Subject: #{subject}
Date: #{Time.now}

#{message}
EOF

conn = Net::SMTP.new server, 465
conn.enable_tls
conn.start 'localhost', user, pass, :login
conn.send_message mail, from, *to.split(/\s*,\s*/)
conn.finish