Author: Graeme Fowler Date: To: exim-users Subject: Re: [exim] Mixed mail deliver, or retrying 550 errors.
>From time to time people ask how to retry 5xx responses.
The answer is: don't. A 5xx response is permanent. If you deliberately retry you are likely to get even more pain from remote hosts as you will be in breach of the RFCs for Internet mail.
Address the problem (being in space with problem hosts) rather than the symptom.