> On Jul 30, 2019, at 8:52 AM, Rob Maidment <rob.maidm...@clearswift.com> wrote:
>
> I already have a before-queue content filter (proxy) that I must use:
> http://www.postfix.org/SMTPD_PROXY_README.html
> I would like to make use of a milter as well:
> http://www.postfix.org/MILTER_README.html
> I'd like to know if combining both could cause problems. What does the
> content filter see, for example, if the milter indicates the message should
> be rejected at the RCPT TO stage?
When the message envelope is rejected, the proxy filter never runs.
I would not recommend mixing milters and proxy filters. The milter
can never see the message body because, when using a proxy, smtpd(8)
has no cleanup(8) to which it can pass the milter connection for body
inspection. The milter will only see the message envelope, and it is
not clear that the milter will behave correctly at "DOT" when it never
saw the message body. I could be mistaken. Wietse would know better.
I've not yet used the Postfix milter interface in practice.
--
Viktor.
