Scalable 20k lotus notes user migration.

[Nitecon]

Hi folks, I would like some information on anyone that has done a large scale migration from lotus notes. What is the max amount of users for zcs, and would a 20k user migration be applicable? There are 2 options, either migrating to exchange or perhaps zimbra, and as you can imagine I hope that the answer is zimbra is more than capable and will do just fine.

As I said the amount of users are aproximately 20k and scalable upwards to 50k. Any additional info and considerations etc would be very much appreciated.

Thanks,