To save the files from the outgoing account, assuming IMAP, do this: - check account settings>synchronization&storage to be sure all are available for download - click file>offline>download to ensure you capture all headers and message content - install the addon, importexporttools NG, if not already done - highlight each of the account folders in turn, right click and select the importexport option to export mbox and the save to a local folder on PC - next, reverse the process, by highlighting Local Folders, rightclick, select importexport option to import mbox and locate and select each of the exported files in turn to import to a local folder. - once you have successfully collected the message folders to local folders, you can upload to the Outlook account, if desired, by creating a manual filter for each folder. I suggest that because IMAP was not designed for uploads so you need to monitor the process. Once complete, check that the messages uploaded successfully before deleting the local folder.