search for: yjs8pe5r0vgh2kcvgh0m0y7tuscm51ljm

I;m setting up new server, what are the options for transferring user's mail ? I've tried imapsync, that seems to work well, but, what options do I have for doing accounts or domains where I don't know user's password ? last time I've done, some users had lengthy period of re downloading 'old' mails from new server, is there a way to overcome this ? thanks, V