Which registry keys are effected when RDNS lookup options are performed.
MailEnable queries the registry to determine whether it should perform a spam database lookup for an inbound hosts IP Address. These options can be set via the Administration console, however this article outlines the relevant registry keys used. Reverse DNS Blacklisting does not work on Windows NT 4, and these keys should not be changed.
The following key is queried to determine whether or not RBL lookups are performed and whether they are performed when a mail server/client connects to the server or when the client specifies the recipients of a message. If you change settings in the administration program it may revert this value from 2 to either 1 or 0, since option 2 is not configurable through the interface.
For 64bit Windows
Enable\Connectors\SMTP\Reverse DNS Blacklist
For 32bit Windows
Key Name: HKEY_LOCAL_MACHINE\SOFTWARE\Mail Enable\Mail Enable\Connectors\SMTP\Reverse DNS Blacklist
Value Name: Enabled
Values: 1=Check RBL on Recipient command (RCPT)
2=Check RBL on Connection
The next registry keys queried determines which registry key branches to check for the list of RBL Provides. This contains a comma delimited list of the registry subkeys that need to be enumerated to determine which hosts are active.
Key Name: HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Mail Enable\Mail Enable\Connectors\SMTP\Reverse DNS Blacklist
Value Name: Processing Order
Finally, MailEnable then checks all the subkeys contained in the above registry key and performs a reverse lookup against each provider that has its "Enabled" value set to 1.
How to configure Reverse DNS Blacklisting: Article ME020162
How to create and manage your own RDNS Blacklist Server: Article ME020271
Why is Reverse DNS Blacklisting not available on Windows NT 4.0?: Article ME020161
Which Registry Keys are used when performing Reverse DNS Lookups?: Article ME020127
How to get tough on spam/Blacklisting: Article ME020084
|Product:||MailEnable (All Versions)|
|Keywords:||RDNS lookup registry key reverse dns blacklisting look up lookups dns|
|Class:||INF: Product Information|
|Created:||30/05/2003 11:02:00 PM|
|Revised:||Wednesday, May 4, 2016|