Re: DomainKeys pre-queue filtering

From: mouss (no email)
Date: Tue Jan 24 2006 - 16:44:24 EST

  • Next message: Magnus Bäck: "Re: postfix linux startup scripts"

    Mark Martinec a écrit :
    >>>I believe the Amavis-new (daemon) receives the e-mail via lmtp and does
    >>>it's magic before it hands it off to a Spamassassin content filter.
    >>
    >>amavisd-new can only receive via smtp.
    >
    >
    > It can receive either by LMTP or SMTP (but can forward over SMTP only).
    > Both LMTP and SMTP implementations are fully standards compliant.
    >

    oops. I was meaning "can only forward via smtp" of course (which is far
    enough for me. lmtp is useless unless the "client" wants to deal with,
    which is generally not the case here).

    >
    > With DK the sending site specifies which header fields it wants
    > included in the check. Typically only certain fields are included,
    > and the rest not (like Received, X-Spam, ...). So even if
    > X-Amavis* and X-Spam-* headers are inserted, it is not very
    > likely it will break DK. As far as I can tell, only the following
    > operations in amavisd-new (if enabled) will break DK:
    > - 'defanging' (wrapping the message in extra MIME layer);
    > - (potentially) releasing from quarantine (Resent-* headers inserted);
    > - removing improper header fields made up entirely of whitespace.
    >
    > Nevertheless, it is probably better to do DK checks before a
    > content filter.
    >

    and better yet, it should be done in prequeue. no point in bouncing or
    quarantining for a DK "failure".

    That said, I still think amavisd-new should move to prepend mode. SA
    already did. This will cause support problems, but I think it's the way
    to go. of course, this is off topic here.


  • Next message: Magnus Bäck: "Re: postfix linux startup scripts"





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