Any plans to support setting ESMTP arguments with milter?


I would like to add DSN parameters to e-mails with milter.

If I set these with smfi_chgfrom and smfi_addrcpt_par, I get:
warning: 3ybBmq5Wxvz43: cleanup_chg_from: ignoring ESMTP arguments
"ret=hdrs envid=qid"

I've read <a href="" title=""></a> and it mislead me,
because I thought only 2.6 has these limitations, but checking
cleanup_milter.c it seems 3.2 does the same.

Is this hard to do in the postfix mailflow and are there any plans to
remove this limitation from milter?