How to speed up Exchange to Zimbra Migration

[kaltera]

We are actually migrating our users internally to a full Zimbra platform. However, we do not want to use the PST Import Wizard because it will be too long to import everything and to let users do it, and we can not use Exchange-Zimbra migration tool because it is way too slow !

Do you know how we can do this migration as fast as possible ? Are there any requirements/advices to it ?

Actually with the Exchange-Zimbra Migration tool, we are migrating at the speed of 30 minutes for a 300Mo account and we will have at least 350 accounts to migrate in the next weeks.

Have you already expefienced that kind of Migration ? How did you do to speed up the process ?

Thank you
Best Regards