If you transfer emails to another device, the exact method depends on your Outlook version and email account type. According to your description, your emails are stored to the local computer, and you can export to an .olm file on your old Mac and then import it to your new Mac device. For specific methods, please refer to the documents and steps linked below:
Export emails to Outlook for Mac data files (.olm): Tools> Export> Export to Archive File (.olm)
Import a .olm file from Outlook for Mac: Tools> Import> Outlook for Mac archive file (.olm)
Hope this helps!
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