[exim] AUTH command used when not advertised

Exim 4.72 (Centos 6)


A MTA experienced 20 minutes (circa 1,722 attempts) of:

(from logwatch)

    2015-04-17 22:56:16 SMTP protocol error in "AUTH LOGIN"
    H=(SRV) [88.119.254.244]:50272 I=[xx.xx.xx.xx]:25 AUTH
    command used when not advertised: 1 Time(s)

Have changed:-

    smtp_accept_max                   = 5
    smtp_accept_max_per_connection    = 5
    smtp_accept_max_per_host          = 5

whilst assuming it will not prevent future abuse.


If I create acl_smtp_auth = acl_reject_auth

acl_reject_auth:

       warn message = ${run{SHELL -c "PHP EXIM_ALERT
                          (code to bloke IP address in IPtables......)

       deny message = (rejection message) ......

will this ACL only intercept log-on attempts ?


Thank you.

--
Regards,

Paul.
England, EU.      Je suis Charlie.