Re: backupmx with Postfix

From: Mark Goodge (no email)
Date: Tue Jul 01 2008 - 06:06:03 EDT

  • Next message: Nicolas Letellier: "Re: backupmx with Postfix"

    Nicolas Letellier wrote:
    > On Tue, 01 Jul 2008 10:42:02 +0100
    > Mark Goodge <> wrote:
    >
    >> No. The server that has the mail rejected sends the mail. Consider this
    >> sequence of events:
    >>
    >> 1. User sends mail out via server A.
    >>
    >> 2. Server A contacts server B to pass the message on.
    >>
    >> 3. Server B accepts the mail.
    >>
    >> 4. Server B contacts server C to pass the message on.
    >>
    >> 5. Server C rejects the mail.
    >>
    >> 6. Server B emails the sender to say that the mail was rejected by C.
    >>
    >> You only need to worry about this if you manage server B (as it makes
    >> you a potential source of backscatter). If you manage server C, then all
    >> you need to do is reject mail you don't want.
    >
    > I manage server B (backupmx). Server C is not mine.
    > The problem is:
    >
    > 1. User sends mail out via server A to an non existent recipient like 4-ygbG5_yg> 2. Server B checks the recipient and see it does not exists in recipient_maps (so it does not relay it to server C). The mail is rejected.
    > 3. Is server B send an email to User to inform him that his email has not been received (because of a bad recipient) ?

    No. In this case, server A will send the email, because it will not get
    to step 3 in my sequence above. Instead, you have this:

    1. User sends mail out via server A.

    2. Server A contacts server B to pass the message on.

    3. Server B rejects the mail.

    4. Server A emails the sender to say that the mail was rejected by C.

    Mark

    -- 
    http://mark.goodge.co.uk - my pointless blog
    http://www.good-stuff.co.uk - my less pointless stuff
    

  • Next message: Nicolas Letellier: "Re: backupmx with Postfix"





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