[exim] Connection closed by foreign host

Hi, im running Exim 4.52 on a FreeBSD box. i have a problem connecting to
MDaemon. all attempts to connect return this

mail# telnet mx.technobrainuganda.info 25
Trying 41.220.14.70...
Connected to mx.technobrainuganda.info.
Escape character is '^]'.
Connection closed by foreign host.

yet, across all my other mail server i can connect quite well

su-2.05b# telnet mx.technobrainuganda.info 25
Trying 41.220.14.70...
Connected to mx.technobrainuganda.info.
Escape character is '^]'.
220 technobrainuganda.info ESMTP MDaemon 6.7.8b; Wed, 04 Oct 2006 17:33:48
+0300


the server im trying to connect to is a Windows MDaemon passing through a
firewall, so all connections are forwarded to the MDaemon server

any ideas why this would reject one mail server yet accept another that is
running a similar configuration.


thanks,

Mike