The first catch with this migration has been the differing ways dovecot and courier-imap represent their folder hierarchies. After reading the following piece in the dovecot docs, I figured they’d behave the same way:

We support Courier-compatible Maildir++. INBOX is the ~/Maildir directory, all the other folders named as ”.<folder>.<subfolder>.<etc>” under it, any directories not starting with a dot are simply ignored.

However, While courier IMAP presents subfolders as subfolders of INBOX, dovecot presents them as root folders. so:

• /INBOX/lyx-devel

becomes

• /lyx-devel

So my filters will need a little tuning.

On the plus side, squirrelmail is running smoothly, while it’s not as pretty as the IMP, it’s perfectly functional and much faster.

My next challenge is to try and get Postfix configured for all the domains I host and with all the external forwarding working.