Many errors relating to - Winsock error code: 10060 win32

Looking through the SMTP send logs I've come across lots of errors mentioning this:

Winsock error code: 10060, Win32 error code: 10060, Error Message: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond 159.15.129.84:25"

AND

,,"Failed to connect. Winsock error code: 10061, Win32 error code: 10061, Error Message: No connection could be made because the target machine actively refused it 192.64.119.254:25"

There are over a 1200 winsock related errors per day in each SEND log.

Any help with this would be greatly appreciated.

Thanks,

DG