After working with Zimbra a while I am starting to plan our migration. I have 200+ accounts without a critical look, no more than 225, with varying amounts of mail. The top thirty mailboxes spanning 15gb to 1 gb. Testing the migration using the Zimbra tool (ZCSExchangeMigrationWizard-220.127.116.116.exe) I had some success solving many problems by making recommended adjustments to the registry and Zimbra auth timeouts.
Currently it looks like it may take as much as three days to move our mailboxes so I am looking for any previous use/experience at speeding that time up. I am currently looking at running all mailboxes through once, then nightly until the cut over as that should make things go much faster. I can and probably should move the migration into the server network were I can make use of the 1gb network.
Any other advice on making this process faster?