Rules Manager has an archiving facility offering more options than the standard Outlook archive.
To start archiving, select Rules Manager -> Tools -> Archive... from the menu. This will open the Archive window, from where you can set the options and start archiving.
Note that while archiving Outlook may be less responsive for normal use - this is due to the mail being processed in the background. It is advisable to set the archive process going when you are likely to be away from the machine (e.g. overnight). Note that you can cancel the archive process once started by selecting Rules Manager -> Tools -> Cancel archive from the menu.
The archive function has been improved in v1.8.4 of Rules Manager (and above), and is much faster.