"David F. Skoll" <dfs@roaringpenguin.com> writes:
> [...]
> We sell a commercial anti-spam system implemented as a milter, and we
> have had pushback for being tied to Sendmail.  Some large customers
> and potential customers grumble about the need to have a Sendmail
> relay, and typically they propose Postfix as the alternative.  Postfix
> now fully supports milter, so at some point we will look at
> integrating with it.

Have you heard about any *serious* attempt to provide core functionality
provided by milter protocol via *open* protocol? [e.g. LMTP based]

[AFAIK Milter *protocol* (not API) has never been documented by sendmail
.org ]

> [...]

--
[pl>en: Andrew] Andrzej Adam Filip : anfi@priv.onet.pl : anfi@xl.wp.pl
Open-Sendmail: http://open-sendmail.sourceforge.net/
Live within your income, even if you have to borrow to do so.
-- Josh Billings

[ Post a follow-up to this message ]

Andrzej Adam Filip wrote:

> Have you heard about any *serious* attempt to provide core functionality
> provided by milter protocol via *open* protocol? [e.g. LMTP based]

No, not really.  Postfix does have an open SMTP-based filtering
protocol, but it's not as full-featured or flexible as Milter.

> [AFAIK Milter *protocol* (not API) has never been documented by
> [sendmail.org ]

Correct, and it's theoretically an internal API subject to change.
However, it's stable enough that the Postfix author(s) felt comfortable
reverse-engineering it and implementing the MTA side of milter.

Samba has succeeded quite nicely in implementing undocumented and
ever-shifting protocols; Milter is at least two orders of magnitude
simpler to reverse-engineer and support.

Regards,

David.

[ Post a follow-up to this message ]

In article <242b$476d4072$d1d97a75$20187@PRIMUS.CA>,
"David F. Skoll" <dfs@roaringpenguin.com> wrote:

> Andrzej Adam Filip wrote:
> 
>
> No, not really.  Postfix does have an open SMTP-based filtering
> protocol, but it's not as full-featured or flexible as Milter.
> 
>
> Correct, and it's theoretically an internal API subject to change.
> However, it's stable enough that the Postfix author(s) felt comfortable
> reverse-engineering it and implementing the MTA side of milter.
>
> Samba has succeeded quite nicely in implementing undocumented and
> ever-shifting protocols; Milter is at least two orders of magnitude
> simpler to reverse-engineer and support.

Or better...

After all, Samba has a reference implementation which it has to match
that can only be examined as a black box, while anyone trying to
replicate Milter has BSD-licensed source code for the reference
implementation.

The problem there is apparently that some of Milter requires an MTA
design better suited to the last century. MeTAl and Postfix have had
similar gaps in their implementations, and while I have not dug deep
into the code to get a direct understanding of the details, I trust Dr.
Venema's descriptions of the challenges.

--
Now where did I hide that website...

[ Post a follow-up to this message ]