Our old server is a qmail system, and when I run the imap sync I get the error I need to run it with the --sep option.
OK, no problem, except I don't know what I am supposed to enter in --sep '?'

If I feed it something, I have tried a space and an _, it tries to run and errors:

'BAD parse error: invalid date format'

Can someone help me out and give me some pointers on how I can migrate all of our mailboxes off of the old server