Re: [exim] changing mailstores

I do not have access to MailstoreA - nor do I really have access to MailstoreB, I ONLY have direct access to the mail routing host which I manage.

Hence my very specific questions related to what happens if I queue the email on the router and the routing data is updated.

Does exim calculate the routing data and cache that information so when it retries a delivery it uses the cached data, or will say ah retry time is up and run the delivery back through the routers for the mail that is queued and so pick up the new routing data?

Ideally I would like the routing data updated prior to the mailstore migration and know that the accounts already exist on mailstoreB and so will accept email, but I am not in control of that data I can only use what I am given; ultimately it comes from a central data source that again I do not manage.

Simply holding ALL email going to mailstoreA is not an option as we are not migrating all users at once - there are roughly 45,000 of them and rather a lot of data - so I am very dependent on either the routing data being updated in advance for batches of users, or have to hope that exim will queue mail if I get the SMTP end shutdown on MailstoreA - and then redeliver appropriately.

Paul