[Exim] synchronization error (input sent without waiting for…

Hello list,

I just want to ask once more how to avoid these messages

SMTP protocol violation: synchronization error \
(input sent without waiting for greeting): rejected connection from H=....

My internal Lotus Domino Server tries to send mail over
my exim-4.24 Mailrelay and gets these messages.

How can I configure exim to accept these messages from my
internal mailserver ?

The same problem appears when I perform a
netcat smtprelay 25 << EOF
HELO mail
MAIL FROM: test@???
RCPT TO: target@???
DATA
From: test@???
To: target@???
Subject: test it

....this is a test