Hello,

I have setup a Postfix mail server for incoming mails that is required to never reply to external enviornment i.e it will accept all incoming mails and never reply anything that can be used as a trace to locate and verify it's existence.

I have implemented the Postfix anti-UCE configuration by using the following settings in postfix main.cf for countering spam generating mail servers:

'smtpd_recipient_restrictions = reject_rbl_client zen.spamhaus.org, reject_rbl_client bl.spamcop.net'

Now i have certain doubts/questions:

1. How Postfix is able to communicate with Black hole list providers i.e How this whole process works?, e.g here they are zen.spamhaus.org, bl.spamcop.net, so that i can test the performance of whole process.

2. Can a header be added in the received mail regarding the status of the results of the above verification process, since i will not reply any traces from my incoming mail receiving Postfix server, so i need this feature?

Please post relevant links for reference.

Thanks in advance!!!

Ashish