SMFIP_RCPT_REJ Milter support (was: pre-queue mode libmilter status and performances)

[Wietse Venema]

The Postfix 2.6 Milter interface now implements SMFIP_RCPT_REJ,
meaning that postfix can report rejected recipients to Milter
applications.

Postfix will report the following macro values, as decribed in
Sendmail 8.14.0 documentation:

    {rcpt_mailer} = "error",

    {rcpt_host} = enhanced status code (e.g., "5.7.1"),

    {rcpt_addr} = reason to reject (e.g., "Relay access denied").

This will be available in release candidate postfix-2.6.0-RC2
and in experimental release postfix-2.7-20090426.

        Wietse