> On Feb 26, 2017, at 12:26 PM, Marek Kozlowski <m.kozlow...@mini.pw.edu.pl>
> wrote:
>
>>> smtp inet n - n - - smtpd
>>> -o content_filter=spamassassin
>>> -o receive_override_options=no_address_mappings
>>
>> Mail that comes in via SMTP is (initially) force-routed to the
>> above specified content_filter transport.
>
> Can you explain more precisely what you mean by saying "(initially)
> force-routed "?
The first time the message hits the queue (prior to re-injection).
Since smtpd(8) added a content_filter setting to the queue file,
normal transport selection is preëmpted by the content filter.
> According to my tests and logs it happens AFTER (the first invocation
> of) the `cleanup' service.
Of course, since the flow is smtpd(8) -> cleanup(8) -> incoming queue
where qmgr(8) finds the message and schedules delivery via the appropriate
agent.
>>> Why does `qmgr' for the first time use `smtp' delivery agent
>>
>> It does not. It uses the content_filter transport if added upstream
>> to the queue file, or otherwise whatever transport table or address
>> class implies.
>
> But in the above configuration the `content_filter' is added only to
> `smtp'..?
No, the filter is added on *input* via SMTP, that is the "smtp inet"
service provided by smtpd(8). Don't confuse input with output.
* SMTP input: smtp inet ... smtpd
* SMTP output: smtp unix ... smtp
--
Viktor.
