Re: Forwarding Setup

From: Philon Terving (no email)
Date: Mon May 16 2005 - 15:25:55 EDT

  • Next message: Victor Duchovni: "Re: Arbitrary lmtp(8) usernames?"

    hello Charles,

    > a) forward messages from to
    > with it going through the message labs
    > filter. To get message labs to take it correctly, the message has to
    > appear to be for when it gets there.

    have a look at the Postfix documentation. IIRC there's something about
    sendmail-style virtual domains and postfix-styled ones. One of these
    should suit your setup.

    For outgoing email there is a rewriting engine, which could even mask
    domain names and rewrite the old From: to the new domain.

    > b) I use SMTP auth to make sure users are allowed to relay messages, I
    > need a way to set postfix so unless a connection is using a valid SMTP
    > auth user or message labs, it drops the message, basically I need to
    > protect my users from direct IP spamming / viruses.

    you would have to configure the MTA to allow SASL-authenticated mails
    and possibly set the allowed domains (mydomain or mysubnet, look into
    main.cf) to the IP-range of the message lab.

    > One idea I had was to somehow check the headers of all messages, and if
    > they haven't been touched by message labs to send them to message labs
    > so they can filter then send them back to us. However that opens us up
    > to spoofed header attacked (and I don't have a clue how to setup that
    > sort of filter)

    sounds to complicated for me. Anyhow, IIRC even SSL-key based relaying
    could be a possibility.

    regards,
    Philon


  • Next message: Victor Duchovni: "Re: Arbitrary lmtp(8) usernames?"





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