SMTP loadbalancer haproxy and logs

My haproxy configuration running prefectly. A simple LB with two smtp servers. But in both smtp servers only report smtp connections from haproxy server and I want to log en every smtp server the original ip from the sending source server. Is it possible?

global
  maxconn 500
  log 127.0.0.1 local0
  user haproxy
  group haproxy
# debug
defaults
  log global
  mode http
    stats enable
    stats auth hadmin:XXXXXX
  balance roundrobin
  maxconn 500
  option httplog
  option abortonclose
  retries 3
  option redispatch
  clitimeout 15000
  contimeout 30000
  srvtimeout 30000

listen stats :80

        mode http
        stats enable
        stats auth hadmin:XXXXX
        stats refresh    20s

listen smtp :25
        mode tcp
        maxconn 500
        option tcplog
        balance roundrobin
        server smtp1 xx.xx.xx.xx:25 check inter 10000
        server smtp2 xx.xx.xx.xx:25 check inter 10000

-- 
Regards;
Israel Garcia