[exim] smtp protocol violation question

Hi

I've from internal server that send automatically mails, some times in
to exim I found the follow error:

2005-06-28 12:01:35 SMTP protocol violation: synchronization error
(input sent without waiting for greeting): rejected connection from
H=srv-snmp [xxx.xxx.xxx.xxx]

I'me trying to disable this control for this host.
I'm using exim4.44 and I'm reading documentation of exim 4.4x.
I've found the follow option:

smtp_max_synprot_errors

But I'm sure that solve it.
I've try pipelining_advertise_hosts but don't solve it.

Someone have idea to solve it?

Andrea