OpenDMARC milter domain based

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OpenDMARC milter domain based

Egoitz Aurrekoetxea-2
Good afternoon,

Can a Postfix instance have a destination based milter (for being able to bypass DMARC check for some customers that ask for it) and finally for everybody a filter action calling Amavis?. 

I mean can a content filter be called from a restriction class (with filter for instance)?. But, later the mandatory filter action for Amavis, should happen for everybody. I say this, because I know that only one FILTER action can exist...

How do you usually do this?. Or you just pass DMARC for every users?.

Regards,

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Egoitz Aurrekoetxea
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Re: OpenDMARC milter domain based

Wietse Venema
Egoitz Aurrekoetxea:
> Good afternoon,
>
> Can a Postfix instance have a destination based milter (for being able to
> bypass DMARC check for some customers that ask for it) and finally for
> everybody a filter action calling Amavis?.

SMTP does not receive any destination until after the fourth step:

1 - receive connection
2 - receive ehlo
3 - receive mail from
4 - receive rcpt too (there may be more than one!)
5 - receive data
6 - receive headers
7 - receive body
8 - receive end of nessage

Engaging a Milter in the middle of an SMTP conversation is problematic,
especially because Millters cannot skip SMTP protocol stages, and
because Milters can reply with 'reject' at many SMTP protocol stages.

        Wietse
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Re: OpenDMARC milter domain based

Egoitz Aurrekoetxea-2
Hi Wietse,

Thank you so much for the advise...

I'm planning how to implement all this :)

Best regards,

El mar., 13 oct. 2020 a las 20:20, Wietse Venema (<[hidden email]>) escribió:
Egoitz Aurrekoetxea:
> Good afternoon,
>
> Can a Postfix instance have a destination based milter (for being able to
> bypass DMARC check for some customers that ask for it) and finally for
> everybody a filter action calling Amavis?.

SMTP does not receive any destination until after the fourth step:

1 - receive connection
2 - receive ehlo
3 - receive mail from
4 - receive rcpt too (there may be more than one!)
5 - receive data
6 - receive headers
7 - receive body
8 - receive end of nessage

Engaging a Milter in the middle of an SMTP conversation is problematic,
especially because Millters cannot skip SMTP protocol stages, and
because Milters can reply with 'reject' at many SMTP protocol stages.

        Wietse


--
Egoitz Aurrekoetxea