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Re: [Asrg] article: port 25 blocking

2005-04-14 18:07:28
William Leibzon wrote:

2. A non-standard port that is 100% open just like regular SMTP is bound
   to soon be known and start to be abused. It has to be some type of
   restricted profile smtp with authentication (which is what submit is,
   so why reinvent it...).


Right--there's no point in blocking port 25 if you just open up another port to plain unauthenticated SMTP. All you're doing then is inconveniencing many people by changing the standard port number for SMTP; you're not actually improving security at all. Botnets will just start probing all the common SMTP ports rather than the standard one.

On the other hand, if you implement SMTP authentication, there's no need to block port 25, and you make the bot-programmer's work harder, or even impossible if the user's mail client uses a properly-implemented lockable keychain.

So instead of wasting time playing move-the-port and annoying people, just implement SMTP authentication. I mean, even my Palm handheld and my mobile phone know about SMTP AUTH these days.


mathew

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