[exim] changing mailstores

Hi,

I will shortly be going through the process of changing mailstores for a
large group of users and have a couple of questions.

As part of the process I intend to shutdown SMTP on mailstoreA in order
to force mail to queue on my Exim routing host - this I am happy with.
However changing the mailstore requires changing the routing data in the
underlying database used by Exim so address xyz@??? routes to
mailstoreB - again updating the underlying database is something I am
happy with.

My questions are based on the following: since Exim has queued the mail
on the basis that it knows that it cannot send mail to MailstoreA how
does it update the routing information for the mail, so:

1. Will Exim, pick up the change in routing information when it next
attempts delivery based on the retry timeouts (or when I kick it with a
-qf or even -qff to be enthusiastic)?

2. If 1. is not a possibility - how do I get the queued emails to have
updated target routing information and so go to the other mailstore?

Many thanks

Paul