[exim] Exim + HAProxy

QUESTION
Question about the use of haproxy with exim.

In HOST HAProxy
..backup smtp_out balance roundrobin    mode                tcp    timeout server 20s    timeout connect 4s    option smtpchk     server  smtp2   smtp2:25 send-proxy check     server  smtp3   smtp3:25 send-proxy check 
In HOST smtp2(3)$exim4 --versionExim version 4.92 #3 built 13-May-2020 16:01:31
/etc/exim4/conf.d/main/00_exim4-localhosts_proxy = 192.168.122.192 "(IP haproxy)
/etc/exim4/update-exim4.conf.confdc_eximconfig_configtype='smarthost'dc_other_hostnames='smtp2'dc_local_interfaces='0.0.0.0 ; ::1'dc_readhost=''dc_relay_domains='*'dc_minimaldns='false'dc_relay_nets=''dc_smarthost='receptor'CFILEMODE='644'dc_use_split_config='true'dc_hide_mailname=''dc_mailname_in_oh='true'dc_localdelivery='mail_spool'
/var/log/exim4/mainlog2020-11-05 11:35:54 SMTP protocol synchronization error (input sent without waiting for greeting): rejected connection from H=haproxy [192.168.122.192] input="HELO localhost\r\n"


ThanksLuciano