someone is using my email address to spam, is there a way to stop this ?

[James Knott]

Robert Brockway wrote:
> On Sat, 9 Aug 2008, James Knott wrote:
>
> [Discussion of blocking SMTP]
>
>> What would a home router block on?  Is this spam sent by their ISP's 
>> SMTP
>
> Destination ports tcp/25 and tcp/587.  It occured to me the little 
> routers could default to blocking and allow people to open the access 
> if they want.  Not sure I'm totally happy with this though, from a 
> philosophical POV.

Wouldn't blocking those port prevent people from sending mail?  
Firewall/routers should already block incoming ports.  As I understand 
it, the problem is caused by malware generating the spam on hijacked 
computers.  How would a firewall tell the difference from legitimate 
mail from a user, if only filtering port 25.
>
>> server or another?  Many ISPs block port 25 from off their network.  
>> I often
>
> I'm not sure how wide spread the practice is right now.  Rogers 
> certainly does it.

Yes, they block port 25, but provide an alternate port for legitimate 
off net mail.
>
> An alternative would be for them to transparent proxy the SMTP ports 
> so that any attempt to reach an outside MTA would have to go through 
> their MTAs.  I expect the reason they don't do this is that it would 
> add a lot of load.
>
> RBLs help to block spam from end-user systems too.
>
> Cheers,
>
> Rob
>


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