[Dshield] Users don't pay attention

Abuse abuse at what4now.com
Sat Aug 20 02:49:13 GMT 2005


** Reply to message from Craig Webster <craig at xeriom.net> on Sat, 20 Aug 2005
03:19:58 +0100

> A few ISPs in the UK block outgoing port 25 which is great for  
> reducing the amount of spam originating inside their network getting  
> outside but is a bugger if you wanted to do something like - shock,  
> horror - use some other smtp server. Luckily my ISP isn't one of them.

My ISP has started to block port 25 on all of its dynamic IP dialup/DSL users. 
Soon to be followed by their static IP DSL users (which includes me) and I do
not have a problem with this.

You can still use another email server.  You just need to send your email out
from your ISPs email server.  I do this all the time, the FROM:, and REPLY-TO:
show my email address of the other email system but if you look at the headers
you can see it did not originate there.  I have been doing this for years even
though I have not been blocked, it was just convenient.


> These ISPs will block the useful ports and lock you into their  
> services no problem under the guise of being the superhero of the  
> story but as you say, it's unlikely that they'll ever monitor or  
> block the vast majority of their traffic. It's simply easier to say  
> "It's the bad guys fault. Now buy our services."

I DISAGREE loudly.

I think blocking port 25 is a very good strategy as this blocks most of the
compromised computers (which is the main source of spam).  If you want to run
your own email server then set it up to relay all of your out bound email
through your ISPs email server.  You can still receive email directly into your
email server without any problems.

Please explain to me why this does not work?


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