Re: [exim] Retry on 550 errors

Dave Lugo wrote:
> On Tue, 5 Dec 2006, Marc Perkel wrote:
>
>
>> I know it's a permanent error. Here's the situation. I do front end spam
>> filtering. What happens sometimes is Iset up a new customer and they
>> point their MX to me and I clean the spam and forward on to them. It
>>
>
> I do that too at $dayjob.
>
>
>
>> works for an hour and then their server realizes it's not the lowest MX
>> anymore and starts bouncing everything I forward. I don't know about
>> this unless something alerts me like the customer calling about reports
>> of email bouncing.
>>
>
>
> I've _never_ seen this happen, and I've worked at my current employer
> for ~7 years, and a lot of domains.
>
> Perhaps the pre-cutover checklist you're working from is incomplete?
>

That's possible. How would you know in advance that the target server
will start to refuse email once the MX has changed?