# Dependencies: `gem install ruby-gmail`

require 'gmail'
require 'csv'

email_subject = "subject line"

email_body = File.open("email.txt", "rb").read

username = "username"
password = "password"

gmail = Gmail.new(username, password)

addresses = []

# contacts.csv exported from Gmail contacts
CSV.foreach('contacts.csv') do |row|
  addresses.push(row[14])
end

# Remove header
addresses.shift

addresses.each() { |address|

  email = gmail.generate_message do
    to address
    from "Your Name <you@email.com>"
    subject email_subject
    body email_body
  end

  gmail.deliver(email)

}

gmail.logout