Re: [Exim] Failing behviour based on SMTP codes.

On 2000-10-17 at 17:33 +0100, John Sloan gifted us with:
> Is it safe to assume that because the backup MX refuses to accept a
> message of that form that the primary MX would as well? This seems to be
> the implication of treating an 5xx error from any MX for a domain as a
> permanent bounce.

Yes. This is part of what an MX is about. An MX is not simply a
"smarthost for just these domains". It's a backup mailserver, and if it
rejects with a permanent error, it's legitimate to assume that the
primary would too.

> There is certainly an argument that this should be the case - that if you
> allow another server to be a backup MX for your domain then you're giving
> it the authority to bounce messages on your behalf.

Yep. If you dislike the policies of your ISP, register a domain;
perhaps use dyndns or one of the other free services; if your ISP blocks
incoming SMTP to users which isn't via them, change ISP.
--
Civilisation: where they cut down the trees and name streets after them.