Re: [Exim] Dealing with 451 errors

On 9/11/2002 at 5:50 PM mark@??? wrote:

>Hello,
>
>so it issues a 451 error code.
>
>Now, what should site 'B' do in response to this?

From my understanding of SMTP response codes, 4xx is a temporary failure, 5xx is a permanent fatal error.

>
>Should it sit on the message for a while, periodically
>retrying it? Or should it immediately fail the message
>and bounce it back to the original sender as a permanent
>error? What would Exim do if it was running on site 'B'?

Since the code 4xx indicates a temporary failure, the relaying server should periodically retry it, so when whatever the cause of the 4xx error is resolved, the message can be delivered. Only upon receipt of a 5xx error should the message be immediately rejected by the relaying server.

Jeremy