Spamhaus Project Public Mirrors using Microsoft Exchange
This details how to use the Public Mirrors with Microsoft Exchange, configuring it to do rejections at the SMTP level.
These instructions apply only to Exchange 2010 and above.
Configuration
Run an Exchange Powershell with administrator privileges and then type the following:
add-IPBlockListProvider -Name 'Spamhaus ZEN' -LookupDomain 'zen.spamhaus.org' -Enabled $true -BitmaskMatch $null -IPAddressesMatch '127.0.0.2','127.0.0.3','127.0.0.4','127.0.0.9','127.0.0.10','127.0.0.11' -Priority '1' -AnyMatch $false -RejectionResponse 'Connecting IP address {0} has been blocked by Spamhaus ZEN. See http://www.spamhaus.org/query/bl?ip={0} for further details.'