We have a Exchange 2000 server that is constantly relaying spam.
It is not an "Open Relay Server". But it is forwarding spam from other servers.
I can not turn off Relaying because I have POP3 Clients around the world. I have it set to only realy from Authenticated users, but this allows any SMTP Server to relay through my server.
My plan is to allow relaying from only one subnet. I can require all of my users outside of my domain to use a VPN to access there mail. By doing this I can insure that they all are in the same Subnet.
Will this work, if not why?
Also is there a better way to stop this from happening?
It is not an "Open Relay Server". But it is forwarding spam from other servers.
I can not turn off Relaying because I have POP3 Clients around the world. I have it set to only realy from Authenticated users, but this allows any SMTP Server to relay through my server.
My plan is to allow relaying from only one subnet. I can require all of my users outside of my domain to use a VPN to access there mail. By doing this I can insure that they all are in the same Subnet.
Will this work, if not why?
Also is there a better way to stop this from happening?