How can we manage old emails in Engage?

We're moving to E10 shortly and will be using Engage.  We were Eloqua for Microsoft Outlook (EMSO) users in E9.  In E9/EMSO, when an email was no longer needed (example: an event we promoted was now over), we would archive the email.  This hid the email from the EMSO users, but we still collected metrics from it.  Plus, we could go back and find it, copy it and update for new purposes (example, a yearly event).

It is my understanding the E10 does not offer archiving.  How does one manage Engage emails, getting them out of the folders of the users when they are no longer needed?

We had thought about moving them to sub-folders called "Archived emails - do not use" but the last time I demoed Engage, it didn't recognize folders.

I would greatly appreciate ideas and experiences.  Thank you.