[Mailmunge] Add Header based on condition in filter_recipient{}

[list at ptld.com]

> because of the fact that Postfix doesn't allocate
> a queue-ID until the first valid RCPT To: command...

Just to share the knowledge.

I found out there is a setting in postfix to assign the queueId after a successful MAIL FROM before the RCTP TO, instead of waiting for DATA.

     http://www.postfix.org/postconf.5.html#smtpd_delay_open_until_valid_rcpt

If you want to include that in the docs about the qid and differences of sendmail vs postfix.