Moving email to another account
Moving email using Apple Mail
Before you are able to move mail between accounts you would need to have bother your SU account added as an exchange account in mail and the other account you would want to move the emails to added to your Apple Mail app, which you can do by adding accounts under “Internet Accounts” in settings.
Once both accounts are in mail you should see their account folders appear in the mail app sidebar. You can now select emails individually or in groups and move them by dragging to the inbox or a folder on the other account.
If you have emails sorted into folders you can also move entire folders into the other account by dragging the folder to the area of the other account.
Gmail accounts do not use IMAP folders like traditional email services do but rather use Labels in a similar way. Due to this moving emails into folders or moving whole folders to a gmail account will move the messages but they may not be sorted into the correct labels for it to reflect the same folder organization that shows inside the Mail app.