Check this one out: Lotus Notes to Outlook or Exchange.
And check out this TechTarget post here.
You use the nupgrade.exe program that is installed with the Administration client. You must have Outlook configured and pointing to your PST on the local machine to make this work. You launch nupgrade.exe from a command prompt with the /3 switch, and you are off and running.
(THE LOCAL MACHINE PART IS HUGE! THIS WILL NOT WORK OVER THE NETWORK!)
Also, you can just export the Outlook stuff and import the documents into a document library using this software.
Here’s a thought, if you installed outlook as a mapi (corporate) client, then you can just configure Notes as another mapi account in outlook (which delivers mail to the lotus notes store: database), and drag the emails from the pst account to the Notes account. (haven’t tried this, unfortunately I didn’t install outlook as a corporate account).
If when you configured your outlook to collect e-mail, you left mail on the server, you can also configure a pop account in Notes to collect the e-mail from the inbox.
I have also read about tools from Binary Tree. let me see if I can find more information! Have you already tried this? Any errors or issues?