maillog error while enable emailing on zabbix

Dear All,

i am getting the following error at maillog while i try to enable emailing on Zabbix server

tail /var/log/maillog
May 14 10:03:19 localhost sendmail[21522]: o4H63J8U021522: monitor-xxxxx.com [127.0.0.1] did not issue MAIL/EXPN/VRFY/ETRN during connection to MTA

the above message is repeated continously!

that’s not caused by emailing, but by the check you have on port 25 - zabbix just checks whether there’s something listening on that port, but not sending any message. these connections are what you see in the logfile.