For some inexplicable reason, I started getting an error message when trying to access one of my POP accounts with Entourage. Of three accounts, two worked fine, but my main account kept giving me an error when trying to download the messages. It read: "Error. An unknown error (-5000) occurred. Explanation. Could not retrieve mail. Account name: 'my pop address'"
I tried rebuilding the database and even made a new database by renaming the database in the Main Identity folder in the Microsoft User Data folder, all to no avail. I tried setting up a new account after trashing the Entourage preferences in my User Folder/Library/Preferences. Entourage let me set up a new account with the same settings as the old main account, and even when I ran Verify my Settings, the results were promising: Entourage stated that my "settings were verified" ... except it still would not download my messages and kept giving the -5000 error.
Microsoft's web site has nothing to say on -5000 errors and the Entourage Help Page had nothing to report, either. Then I trashed old identities and other folders in the Microsoft User Folder one by one until Entourage refused to load. The culprit turned out to be the Entourage Temp folder. When this was removed, I got the following message: "You do not have write access to the Entourage application folder. To run Entourage, you must have the administrative user remove the Identities folder from the application folder. For more information, see the Entourage Read Me file."
I looked at the Entourage Read Me file, but it did not tell me anything that would seem to resolve the error. However, when I looked at the permissions of the Entourage Temp folder with Get Info, they were clearly not correct. So I set the Owner to me with Read and Write access, I set the Group to Admin with Read and Write access, and left the others at Read Only.
After this, Entourage worked as normal, and I was finally able to retrieve my mail.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20050419202258730