Then this "U2U Email Sharer for Outlook 2007" add-in might be something for you.
With this add-in you can publish your email message to private or public SharePoint libraries. Other user can then connect these libraries to Outlook and browse/search through the emails.
If you do not want to read any further but want to immediately download the U2U Email Sharer software? Click here
The Outlook add-in looks up all the connected SharePoint libraries currently available in Outlook(Fig.1) When you want to save an email to a connected SharePoint list you just right-click the email and select 'Publish To SharePoint'(Fig.2). For each SharePoint library connected in Outlook the add-in creates a menu item under the 'Publish To SharePoint' menu. Click on the menu item with the name of the SharePoint library you want to publish the email to. The email will be saved to the library.(Fig.3)
Fig.1: Connected SharePoint libraries currently available
Fig.2: Available SharePoint libraries are displayed in menu.
Fig.3: Email saved in document library.
Fig.4: Email available in Outlook SharePoint folder.
Find the download and setup instructions here.