Transfer mail from one (corrupt) Open Directory account to new one

Hi

When I upgraded To Server (3.0.3) my Open Directory became corrupted. Despite many attempts I could not retrieve it despite having backups on Time Machine. As a result I removed the Open Directory and rebuilt the accounts from scratch.

Everything is now working however, I want to bring back the emails that were received in the old corrupted accounts into the new (now working but with no historic email) accounts.

Please can someone point me in the right direction as to how I can achieve this. The majority of the emails are still on the server but under the old account names and I have a full back on Time Machine.

Many thanks

Rob