customizing postfix logs with a mailing id

[Stéphane MERLE]

Hi,

I would love to customize a little the logs of postfix. We are using 
postfix for massmailing and I'd like to be able to get statistic on 
mailing, so I would like to tag each mail with the mailing number so I 
can split the log files by mailing and then get the bounced/sent/spam 
detection for each mailing and get back to our users with specific data 
for there mailings.

Is that possible ?

Thanks.

Stéphan