Today a customer called me to ask if Microsoft Office 2007 Standard edition supports the Exchange 2010 on-line archive.
As I recalled a message on the Exchange team blog, telling that Office 2007 finally supported the Exchange on-line Archive. I replied "Yes, Outlook 2007 supports the Exchange 2010 On-line archive". http://blogs.technet.com/b/exchange/archive/2010/12/20/3411710.aspx
He replied a bit surprised claiming that all his Office 2007 professional Editions see the on-line archive, while all the standard editions do not.
My first hunch was that those clients must be missing the patch which enables the on-line archive. Yet the customer replied that all patches where installed, even the February roll up for office 2007 (http://support.microsoft.com/hotfix/KBHotfix.aspx?kbnum=2475891&kbln=en-us).
Investigating the issue a bit further revealed that not all Outlook 2007 versions are the same. Following link explains that Office 2010/2007 standard editions do not support the Exchange 2010 On-line Archive: