There are settings within the plugin that allow for this, what this will do is archive the record to any Lead or Contact record with the matching email address. If you only want to archive to one module then we recommend not using this process.
On Outlook, go to the Add-Ins menu
Select Sugar-CRM plug in settings
Go to the Mail tab and check the following boxes
Enable auto-archive
Automatically archive all incoming and outgoing Outlook emails for Contact/Lead
Press OK
If you would like further information regarding what the options within the plug in settings do you can find that 'here'