Hello, I'm taking on a project to update our customer mail server. Currently it's running a Postfix/Courier/Horde setup with no control panel software. I would like to update it to a Postfix/Dovecot/ISPConfig/Roundcube configuration instead. The old server is storing mail in the MailDir format. This should make migrating the mail a lot easier. What I'm not sure about is how to migrate the user accounts. In other posts I've read people are creating the accounts in ISPConfig and then migrating the MailDir files over afterwards. This is not an option for us. We're trying to migrate approximately 26,000 mailboxes. If a password reset is required then so be it, but ideally we'd like to be able to just import the accounts into ISPConfig, then import the MailDir files from the old server to the new server. Does anyone know if this is possible, and does anyone have any tools, scripts, or utilities that they can suggest to help with the migration? Thanks in advance!