Create a new Profile for Outlook
Open Outlook in the new profile
Set up a new IMAP email account attached to the source email account.
Set up a second IMAP email account attached to the target email account.
The folders of each account will appear in Outlook on the left, under their account names.
Drag the folders with emails from the source email account to the target email account


The messages retain their from addresses and all the folders are copied.