unwise filtering policy from cox.net

Paul Jakma paul at clubi.ie
Thu Nov 22 09:03:51 UTC 2007

On Wed, 21 Nov 2007, Barry Shein wrote:

>   xx at example.com
> is going to go to whatever MX example.com returns.

Yes, I'm aware.

> Sean's point was that you can't cause, e.g., eg at example.com alone 
> to go to a server other than the same set of servers listed for 
> AnythingElse at example.com.

Right, his point was that load or policy (" administrators may make 
changes which affect all addresses) would cause a problem, and this 
was, for some reason, due to routing of email addresses.

I took issue with the policy side of the comment. While it's 
possible, it's got nowt to do with limitations in SMTP routing, it's 
just operator error.

> If that (eg at example.com) overloads those servers, even if they're
> valiantly trying to pass the connection off to another machine, then
> you have to use some other method like eg at special.example.com or
> eg at other-domain.com and hope the clients will somehow use that tho for
> BIGCOMPANY there's a tendency to just bang in abuse at BIGCOMPANY.COM.

Right, I do understand that. There are obvious ways to horizontally 
scale inbound mail using MX records and more, so the load issue 
shouldn't be an issue for any given organisation. Least not more than 

However, I didn't comment on the load part of Sean's point.

> If you think I'm wrong (or Sean's wrong) even for a milisecond then
> trust me, this is going right over your head. Think again or email me
> privately and I'll try to be more clear.

I don't think this is over my head.

Paul Jakma	paul at clubi.ie	paul at jakma.org	Key ID: 64A2FF6A
Love thy neighbor as thyself, but choose your neighborhood.
  		-- Louise Beal

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