[FW1] Connection I/O Failure

[NDUKU MUNYARADZI <munyaradzin@FW1-NOSPAMoldmutual.co.zw>]

Title: Connection I/O Failure

Hie Gurus
I have this problem for  you to Help.
Iam using FW-1 ver 4.0 on SP5 on NT4.0. I am experiencing a problem of not receiving external mail on my firewall. I checked in my logs i.e asmtpd logs and found numerous of the following error

 fd: 120 src:193.220.40.22 dst: 196.7.123.203 Connection I/O failure

at the bottom of these errors is this statement
Resolver_gethostbyaddr() Failed.WINSOCK error #11004

What does this mean and how can I resolve the problem?

Thank you in advance

Munyaradzi Nduku