Re: Filtering e-mail headers : To,Cc and Bcc

[Sahil Tandon]

On Dec 8, 2009, at 10:14 AM, "Sharma, Ashish" <ashish.shar...@hp.com>  
wrote:

Hi,


I have a Postfix mail-receiving server.



I have to filter the received e-mail according to the logic:



1.       Only mails sent to the recipient registered on my email  
server would be accepted.

2.       Mails sent to the recipient registered on my e-mail server  
would be rejected if any other recipient of the mail has been  
specified in To, CC or BCC header.



Now I have two options:



1.       Write a mail-filter (milter), parse the incoming headers of  
the mail and implement the logic (I know how to do this).

2.       Using custom postfix feature as listed here: 
http://www.postfix.org/BUILTIN_FILTER_README.html



I have very less idea of option 2,



and Will I be able to achieve my intended logic by option 2?



If yes please give some good examples.



Also, which option would be efficient regarding  performance and  
memory usage wise?

I think you are being overly complex. Read some documentation: postconf 
(5) is a good start to understand how Postfix rejects mail for  
everyone except recipients YOU designate as valid.  For the second  
point, it seems you just need a simple policy service that checks for  
recipient count and rejects mail if it is > 1.  Also note that there  
is no BCC header in mail that arrives on your server.