After several delays and other circumstances we have finally come to within 30 days of our migration from Groupwise! We're very excited to finally get away from Groupwise and finish the migration to Zimbra. With that said, what caveats should we be aware of as that day approaches? There is always an unknown element, so what threw your migration off course or did everything go well?

One question off the bat is - How many users did you run through the GW migration tool at once? We have 1500 users and hope to have the conversion done over a weekend. So far I have setup 4 VMs that will run the migration wizard, but how many users can I do at once?