Switching webmail

[bparker.com]

I am switching webmail from squirrel (too buggy after the migration) over to either horde or atmail. I know that the address book won't automatically flip over when I switch, but does anyone know whether or not user's email folders will automatically move over?

Will users lose all their messages stored in folders in their webmail if I switch?

[snowmaker]

The messages (and the folders) should still be there. The webmail clients all talk to the same email server, which actually has the messages.