IP/Subnet Mask Exchange Server HELP

[mikew]

My Exchange Server dumped my list of denied IP ranges and I'm forgetting what I did regarding subnet masks to block ranges of IPs from many malicious countries.

If I want to block all e-mail coming from an IP range that starts with 41, I thought I would put in
IP Range=41.0.0.0
Subnet Mask=255.255.255.255

If I want to block all e-mail coming from an IP range that starts with 42.163, I thought I would enter
IP Range=42.163.0.0
Subnet Mask=255.255.0.0

This is not working, so I must have something wrong with the subnet masks.

 

[docpadds]

IP Range=41.0.0.0
Subnet Mask=255.255.255.255

You are blocking only the single IP 41.0.0.0 there, you need a mask of 255.0.0.0 to block anything beginning with 41.

 

[mikew]

Thanks! I couldn't remember what I had done in the past, but that was it.