Kouhei Sutou:
> Hi,
>
> Postfix 2.7.0 supports milter protocol 2, 3, 4 and
> 6. Postfix with milter_protocol=6 accepts a connection from
> a milter that uses milter protocol 2. But its milter session
> is broken because Postfix sends SMFIC_DATA event to the
> milter. In milter protocol 2, SMFIC_DATA isn't supported. So
As documented, the Postfix Milter protocol version must match the
application Milter protocol version.
You can patch glitches as you discover them, but that is not the
same as making sure that different versions will always inter-operate.
Wietse
