If you can send and receive emails when you are in Outlook but your address book is not working, you need to check for the following.
Laptops
If you see this issue on a laptop, it could be that your Outlook profile was setup under IMAP and not Exchange. I notice that this happens frequently on laptops because the previous technician knows that when the user is out of the office, the firewall will prevent Outlook from seeing the Exchange server. Sadly, the technicians do not remember that they can install VPN and have Outlook work normally.
