[Exim] unexpected

Morning all.

I have included a snip from my mainlog.

I keep getting the "unexpected disconnection" messages in my logs.

<snip>
2003-05-30 05:37:40 no host name found for IP address 211.139.33.99
2003-05-30 05:38:11 H=(209.212.97.2) [211.139.33.99] F=<ll80zv4z@???>
rejected RCPT <henkins@???>: rejected because 211.139.33.99 is in a
black list at spews.relays.osirusoft.com
2003-05-30 05:38:13 unexpected disconnection while reading SMTP command from
(209.212.97.2) [211.139.33.99]
2003-05-30 05:39:11 H=acayenne-101-2-1-140.w217-128.abo.wanadoo.fr
[217.128.153.140] Warning: found in bl.spamcop.net
2003-05-30 05:39:11 unexpected disconnection while reading SMTP command from
acayenne-101-2-1-140.w217-128.abo.wanadoo.fr [217.128.153.140]
<snip>

Can anyone advise what causes this & if I must ne concerned or not.

Many thanks

Regards,
Tom Kinghorn