Hello Nasium, If you go to delete the contacts( offline mode), when your client connect to Exchange Server, it will try to download the contacts from Exchange Server. If you want to remove the contacts, you can keep client connect to Exchange Server, and remove the contacts or use OWA to remove the contacts, then when you Outlook connect to Exchange Server, it will not rebuild the contacts. Thanks, EvanEvan Liu TechNet Community Support

Not sure how this happened but a user with 50 Outlook 2010 contacts got replicated to about 144k. After spending a few hours deleting them (offline mode) from the contacts and deleted folders they are coming back when I connect to Exchange 2003. How do I get exchange to recognize they have been deleted and not rebuild them? We are using Exchange 2003 cached mode on a Windows 2003 domain. Many thanks!

Hello Nasium, If you go to delete the contacts( offline mode), when your client connect to Exchange Server, it will try to download the contacts from Exchange Server. If you want to remove the contacts, you can keep client connect to Exchange Server, and remove the contacts or use OWA to remove the contacts, then when you Outlook connect to Exchange Server, it will not rebuild the contacts. Thanks, EvanEvan Liu TechNet Community Support