[exim] Retry hint left over after successful delivery

Hi all,

Encountered a strange issue I was hoping someone might be able to explain. Exim 4.69/Debian (although a 4.71 source build seems to do the same).

An email was sent on the 19th to a domain with two MXes:

* first MX responded to 'RCPT TO' with a 4xx code (greylisting, AFAICT)
* second MX accepted the message

However, a retry entry was still created:

R:john@???:<simon@???> -44 13133 SMTP error from remote mail server after RCPT TO:<john@???>: host mx2.SOMEDOMAIN.co.uk [xx.xx.xx.xxx]: 451 Deferred: Temporary error, please
19-May-2010 00:27:48 25-May-2010 22:58:40 26-May-2010 04:58:40 *

Fast-forward to today - the retry time (4 days) has expired, which seems to be causing subsequent messages sent with the same retry key (recipient:<sender>) to bounce *immediately* if both MXes return a 4xx code (which they do, again due to the other end's greylisting).

Is this expected behaviour and/or am I missing something obvious? I imagined a successful delivery would *always* remove the retry hint (in this case, perhaps not even bothering to create one in the first place, since I suspect the delivery process adding the entry was the same to deliver the message moments later, when it tried the second MX).

Thanks,

Simon.