In our environment, we are using Outlook 2010 version 14.0.7. Under the file tab in Outlook, I want a specified user to have the option to go to 'Cleanup Tools' and then click on 'Archive' but it is greyed out. We use Exchange Server 2010 sp1 for mail and 'Enable Archive' is not set on any of the mailboxes. There is one user who has the ability to go to that and I see nothing different set on that user's account, we are all set up identically. How do I enable this feature please?
Enable Archive
doesn't have anything to do with the Outlook client being able to use the Archive function. Enabling Archive in Exchange server enables the Archive Mailbox for the user, which as @HopelessN00b stated, requires an Enterprise CAL. The Archive function in Outlook allows a user to archive their email to a PST file. If the Archive option isn't available in Outlook then it's been disabled by Group Policy.