Sending a Zip File as attachment

require 'digest/sha1'
require 'net/smtp'
  tfile_name="/home/praveen/test.zip"
  toEmail = Array.new
  toEmail << "1NAME \<praveen.kothapalli@techmahindra.com\>"
  fromEmail = "cyberdevdrona@techmahindra.com"
  fromEmailAlias = "CyberDevDrona"
marker = "AUNIQUEMARKER"
part1 =<<EOF
MIME-Version: 1.0
attachment :content_type => "application/zip",
       :body => File.read(tfile_name),
       :filename => File.basename(tfile_name)
Content-Type:"application/zip"; boundary=#{marker}
--#{marker}
EOF

part2 =<<EOF
--#{marker}
EOF

part3 =<<EOF
Content-Type: zip/attachment; name=\"#{tfile_name}\"
Content-Disposition: attachment; filename="#{tfile_name}"
--#{marker}--
EOF

mailtext = part1 + part2 + part3

      Net::SMTP.start('localhost') do |smtp|
                        smtp.send_message mailtext, fromEmail, toEmail
        end

I used this code to send my zip file as attachment but iam getting empty
zip file in mail. Could you please suggest me how to send a zip file as
attachment in ruby.