Q: Is there a way to open Entourage emails with an open-source email viewer, simply by opening the Entourage database file?
CONTEXT: I have old emails in a Microsoft Entourage database, which I'd like to read with an open-source email viewer. I no longer have Entourage on my new Mac.
My Entourage email database file resides at this filepath (930 MB):
/Users/me/Documents/Microsoft\ User\ Data/Office\ 2004\ Identities/Main\ Identity/Database
While your mail is still saved in the entourage database format, I wouldn't know a way to open it in open source email-clients, as it is a mostly undocumented format.
You could however try and get a 30-day trial of Office for Mac 2008, which still includes Entourage, or Office for Mac 2011, which has Outlook and should be able to import the Entourage format.
(Source : http://support.microsoft.com/kb/2413370)
After that you would have to export the mails in the .mbox format, which is recognized by several OSS-Mailclients.