The socket error #10060 that spamfilter reports is more likely a symptom of other problems at the network level then a problem with spamfilter. I suggest re-installing your network drivers.

The error number is a "Windows Socker Error Number", and is a low-level error number provided by Windows API. We intercept some of the most common errors in the code and provide english explanations for them, but not for all. The one you are receiving is for "Connection timed out", and depending on where it occurs will hopefully give a clue as to where SpamFilter is experiencing the timeouts.

For future reference, a partial list or numeric errors is as follows:
 
Socket error 10004 - Interrupted function call
Socket error 10013 - Permission denied
Socket error 10014 - Bad address
Socket error 10022 - Invalid argument
Socket error 10024 - Too many open files
Socket error 10035 - Resource temporarily unavailable
Socket error 10036 - Operation now in progress
Socket error 10037 - Operation already in progress
Socket error 10038 - Socket operation on non-socket
Socket error 10039 - Destination address required
Socket error 10040 - Message too long
Socket error 10041 - Protocol wrong type for socket
Socket error 10042 - Bad protocol option
Socket error 10043 - Protocol not supported
Socket error 10044 - Socket type not supported
Socket error 10045 - Operation not supported
Socket error 10046 - Protocol family not supported
Socket error 10047 - Address family not supported by protocol family
Socket error 10048 - Address already in use
Socket error 10049 - Cannot assign requested address
Socket error 10050 - Network is down
Socket error 10051 - Network is unreachable
Socket error 10052 - Network dropped connection on reset
Socket error 10053 - Software caused connection abort
Socket error 10054 - Connection reset by peer
Socket error 10055 - No buffer space available
Socket error 10056 - Socket is already connected
Socket error 10057 - Socket is not connected
Socket error 10058 - Cannot send after socket shutdown
Socket error 10060 - Connection timed out
Socket error 10061 - Connection refused
Socket error 10064 - Host is down
Socket error 10065 - No route to host
Socket error 10067 - Too many processes
Socket error 10091 - Network subsystem is unavailable
Socket error 10092 - WINSOCK.DLL version out of range
Socket error 10093 - Successful WSAStartup not yet performed
Socket error 10094 - Graceful shutdown in progress
Socket error 11001 - Host not found
Socket error 11002 - Non-authoritative host not found
Socket error 11003 - This is a non-recoverable error
Socket error 11004 - Valid name, no data record of requested type

Jeffrey,

Does the error occur every time that same IP address makes the connection to SpamFilter? If so, you could enable debugging in SpamFilter to trap the SMTP traffic from that IP. Under Settings - Debug View in SpamFilter you can add that IP so that only the traffic from that will be captured.

If the error occurs at different times, from different IPs, it's very possible that a problem is occurring on the server, and that affecsts the network card/drivers. Which then in turn affects SpamFilter.