Outgoing SMTP Servers

Brian Johnson bjohnson at drtel.com
Mon Oct 31 20:12:32 CDT 2011


Sent from my iPad

On Oct 31, 2011, at 1:30 PM, "Jack Bates" <jbates at brightok.net> wrote:

> 
> 
> On 10/31/2011 11:48 AM, Michael Thomas wrote:
>> I've often wondered the same thing as to what the resistance is to outbound
>> filtering is. I can think of a few possibilities:
>> 
>> 1) cost of filtering
>> 2) false positives
>> 3) really _not_ wanting to know about abuse
> 
> On the other hand, you have
> 
> 1) cost of tracking
> 2) support costs handling infections
> 
> It's really an range from "easiest and cost effective" to "doing it right". I personally run hybrid. There are areas that are near impossible to track; this is especially true for wide area wireless/cellular/NAT areas. I always recommend my customers block tcp/25, even to the local smarthosts. Use 587 and authentication to support better tracking. It's a hack, though, as it doesn't stop other abuses and it won't fix the underlying root cause.

Let me know when u can "fix" the root causes. The two I know of:
1. Bad actors
2. Clueless users

> 
> In locations that support ease of tracking, using a mixture of feedback loops with proper support is usually the proper way. This allows notification and fixing of the root cause. In our case, we recommend quick suspensions to demonstrate to customer how seriously we take the problem, and then we point out that the sending of spam/scanning is only the easier to detect symptoms. It is unlikely we'll notice if they have a keylogger as well.

Still not the real root cause, but close. ;)

Largely in agreement otherwise.

 - Brian


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