Hello all.
Did anyone heard about or can suggest mabe a postfix serverside solution in order to insert a counter number into the subject line before the message is sent?
I mean something similar with helpdesk tickets, because I would like to create the possibility for the senders, to make further refference about a speciffic message using it's counter number provided by postfix server.

Generally speaking such a process would require you to set up a filter (/etc/postfix/outgoing-filter-check?) or a milter (Postfix should support milters) or an outbound proxy to inject text in outbound messages which is not impossible, for instance see MTAs adding those disclaimer footers (which are BTW totally devoid of any meaning, judicial or otherwise), DKIM or spam-filtering outbound, but doing that would seem the wrong way to do things. First of all messages get a unique Message-Id anyway (so b0rken threading is a MUA problem) plus helpdesk ticketing software exists, so why not use that?..

Thanks. I am aware about the unique Message-ID and I am also familiar with helpdesk software. The solution I am looking for, is to have all incomming emails numbered(serverside) into their Subject line regardless the sender's email client and excluding an unified system such as an helpdesk software, in order to be further referenced by this number(prefferebly incremental with reset possibilities). The solution, as you mentioned, lays around a proxy, a filter-milter, or similar(see how Hylafax works). This is why I launced this challange for someone who ever used or saw(inside) this working.

Cheers.

You mean Postfix After-Queue Content Filter doesn't work for you?

Hey man! Thanx.

This can be a lead. Let me chew it for a while...

@unSpawn

Thank you very much. You gave me a valid clue.

Cheers!!