Outlook 2007 Error – General Failure When Opening a Link

Does the problem persist with a fresh profile, configured with the new credentials?

You may also have an incorrect password saved in your saved passwords. You can manage your stored passwords from Control Panel -> User Accounts. (I believe the process is slightly different under XP and Vista)

If you drag all the folders off the IMAP server to a local folder, outlook will download all the messages and store them locally. Keep in mind this will also remove those messages from the IMAP server.