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Re: avoiding overload on port 587

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  • Benny Pedersen
    ... make it simple to abuse ... historical microsoft have always being the company with hidded features, but ther is more point in not using port 25 then it
    Message 1 of 54 , Dec 4, 2012
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      Reindl Harald skrev den 04-12-2012 08:12:
      > Am 04.12.2012 07:58, schrieb Tomas Macek:
      >>> 2) why would you setup a submission service that doesn't require
      >>> auth
      >>> from MUAs?

      make it simple to abuse

      >> It's because they never had to. It is a historical problem. Now we
      >> have thousands of customers, that >> never had to authenticate, so
      >> there is no power to force them to do it now.

      historical microsoft have always being the company with hidded
      features, but ther is more point in not using port 25 then it does not
      work or work

      thinking of sender-id ?

      thay failed to understand there was no point in make ther own license
      on using it ?

      > than you have lost any game

      +1

      i have seen lego robots playing chess :)
    • /dev/rob0
      ... Or better yet: replace it with postscreen. ... To clarify, I meant that if those Outlook Expresses are not yet compromised by malware, they will be, soon.
      Message 54 of 54 , Dec 4, 2012
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        On Tue, Dec 04, 2012 at 07:46:10AM -0600, /dev/rob0 wrote:
        > On Tue, Dec 04, 2012 at 11:59:01PM +1300, Peter wrote:
        > > I would still also set up port 587 on the mail.example.com
        > > IP as submission as well and try to encourage your users (at
        > > least the ones you can) to use port 587 from now on.
        >
        > What I would do, on Linux with IPv4 only, is create the submission
        > port and use an iptables redirect for the alternate IP address:
        >
        > # iptables -vt nat -A PREROUTING -p tcp --dport smtp -d \
        > mail.example.com -j REDIRECT --to-port submission
        >
        > This saves the overhead (system and administrative) of running
        > another smtpd on [mail.example.com]:25; he can leave his "smtp ...
        > smtpd" service alone in master.cf.

        Or better yet: replace it with postscreen.

        > I should also add as a reply to Stan in the other subthread: look
        > above at the first quoted paragraph: "Outlook Expresses setup with
        > ... default configuration."
        >
        > Yikes, bad news, very bad. If not doing content filtering nor
        > policy limitation of submission now, he will be soon. And possibly
        > losing his job in any case. Tomas is not in a good place right now.

        To clarify, I meant that if those Outlook Expresses are not yet
        compromised by malware, they will be, soon.
        --
        http://rob0.nodns4.us/ -- system administration and consulting
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