IMPORTANT The procedure described below suggests copying the mailboxes during the import process. You should make sure you copy the original Eudora mailboxes rather than moving them, just in case some problem occurs and you need to go back to the originals.
Create a Local or POP3 mail account in Mulberry, or identify an existing one to use for the import.
Make a note of the name you assigned to the account.
Locate the directory Mulberry uses to store the mailboxes for the account on disk. By default this will be in the Mailboxes directory in the Mulberry application directory. Inside Mailboxes will be an Offline and POP3 directory, used for storage of Local or POP3 mail account mailboxes. Inside each of those will be a directory with the same name as the account. That's where mailboxes will be stored.
Create a new directory inside the account directory on disk - call it something like 'Imports'.
Locate the directory where your Eudora mailboxes are stored.
On Win32: Copy all the files with .mbx extensions into the new Mulberry directory. Do not copy the files with .toc extensions as they are not needed.
On Mac OS: Copy all the mailbox files to the new Mulberry directory. Download the mailbox converter AppleScriptlet (for Mac OS X). Drop the new Mulberry directory onto the AppleScriptlet. This will convert the file types to one suitable for Mulberry, and add the required .mbx extension.
Restart Mulberry and look at your account. You should now see the Imports hierarchy comntaining your imported mailboxes.