ISPs blocking SMTP connections from dynamic IP address space

Lucas Holt luke at
Wed Aug 6 13:24:40 PDT 2003

There are valid servers on DSL ips... I occasionally do IT work for a 
small business.  They are running their web, dns, and email from a 
static IP DSL account through SBC.  They bought a business package for 
this purpose.  They do not spam anyone.

You guys need to rethink this thing.  Reverse DNS checks are ok, but ip 
blocking for legitimate servers is silly.  What if I blocked your mail 
servers and you wanted to do business with me?

Most of the spam I see is coming from Asia, not US DSL/Cable users.

As for all those worms, they could be stopped if enough people 
complained to Microsoft.  People just accept that crappy software.. if 
any other vendor were to release it they would be out of business.  I 
don't read email from my Wintel box for just that reason.

On Wednesday, August 6, 2003, at 02:47  PM, Doug Poland wrote:

> On Wed, Aug 06, 2003 at 11:41:56AM -0700, Nicole wrote:
>>  Yes I too have resorted to blocking Ip's with no reverse DNS and
>>  its amazing how many big companies can fall into this.
>>  As to the Dynamic Space, I also block DSL/dynamicly assigned Ip's
>>  as I fall aware of them. (See Example below) Since some Isp's are
>>  smart enough to identify their dynamicly allocated space it makes
>>  it easy.  So far it is extreemly rare for someone to be sending
>>  mail directly from these DSL/dynamic spaces that anyone wanted to
>>  recieve.
> except those of us running FreeBSD SMTP servers from broadband
> connections with valid reverse DNS
> -- 
> Regards,
> Doug
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Lucas Holt
Luke at
________________________________________________________  (Jewel Fan Site) (Free blogging)

"Only two things are infinite, the universe and human stupidity, and 
I'm not sure about the former."
- Albert Einstein (1879-1955)

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