rogers modem upgrade / port 25

[Jon Thiele]

The main reason ISPs block outbound TCP/UDP 25 is that many Windows trojans
come with a complete SMTP engine that can be used for sending spam,
propagating the trojan and/or DOS attacks.  If the outbound port is blocked,
then this lessens the exposure...

I refuse to use Roger's mail servers since they are not located in Canada.


-----Original Message-----
From: owner-tlug-lxSQFCZeNF4 at public.gmane.org [mailto:owner-tlug-lxSQFCZeNF4 at public.gmane.org] On Behalf Of Scott Ripley
Sent: 19-Sep-05 5:11 PM
To: tlug-lxSQFCZeNF4 at public.gmane.org
Subject: Re: [TLUG]: rogers modem upgrade / port 25


hey all,

> To block open relays, which can be used for spamming.

i can understand blocking inbound connections on port 25:
  - block open relays (as you mention)
  - theoretically people shouldn't be running mail "servers"
  - etc.

but blocking outbound connections on port 25?

i think this essentially "forces" your average user to use Rogers SMTP 
server for sending e-mail...  (yes... i know you could access an SMTP 
server configured to accept connections on another port, etc.)

now why would an ISP want to force most (average) users to use their 
(and only their) SMTP server for sending e-mail?  ;-)

Scott


-----Original Message-----
From: James Knott <james.knott-bJEeYj9oJeDQT0dZR+AlfA at public.gmane.org>
To: tlug-lxSQFCZeNF4 at public.gmane.org
Sent: Mon, 19 Sep 2005 16:55:40 -0400
Subject: Re: [TLUG]: rogers modem upgrade / port 25

Stephen wrote:
> Allen Taylor wrote:
>
>> Pretty well everybody is blocking port 25 now.
>>
>>
> Does anyone understand the rational for blocking port 25?

To block open relays, which can be used for spamming.
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