[exim] SMTP sync problem

hello all,

I have a problem with sync smtp. When i send mail by mail, nothing is
wrong. But when I send several mails, all of them are rejected.

I'm testing from one of my proxy to my smtp server exim. All of them are
in a DMZ and rules are correct.

Here is my log on smtp server:

2005-02-23 18:30:06 SMTP protocol violation: synchronization error
(input sent without waiting for greeting):rejected connection from
H=proxy001.XXXX.fr [10.2.2.2]
2005-02-23 18:30:08 SMTP protocol violation: synchronization error
(input sent without waiting for greeting):rejected connection from
H=proxy001.XXXX.fr [10.2.2.2]
2005-02-23 18:30:08 SMTP protocol violation: synchronization error
(input sent without waiting for greeting):rejected connection from
H=proxy001.XXXX.fr [10.2.2.2]
2005-02-23 18:30:08 SMTP protocol violation: synchronization error
(input sent without waiting for greeting):rejected connection from
H=proxy001.XXXX.fr [10.2.2.2]

etc etc ...

Here is what i have on the proxy :

[root@proxy001 /root]# ./test_smtp 1000
554 SMTP synchronization error
554 SMTP synchronization error
554 SMTP synchronization error
554 SMTP synchronization error
554 SMTP synchronization error


Thanks

Franck