Hi Richard,
Thanks for your reply.
It is not feasible to undo it. You can only delete this OLM folders and import the file again. I’d like to explain that exporting OLM files will not affect your emails in the account unless emails have been missed before in the account.
For missing email issue, it is different with original issue. To avoid confusion for other community members, you can post a new thread with details below in our forum. Then our engineers will focus on the new thread and troubleshoot the issue for you. Your understanding is appreciated.
1. For “I lost a year of archive emails and do not have any current emails.”, when did you lost emails?
2. Do you mean you lost emails after you import OLM files in the new Outlook for Mac or you lost them in the Outlook for Mac 2011?
3. Have you checked emails in Outlook Web App (OWA)?
Best Regards,
Erick