In the setup wizard, check the following:
Did you select the correct Outlook
Synchronization only works with the Outlook folders you
selected in the setup wizard. Contact names in a different database, or in
other folders, won't be synchronized. To select a different database or
folders, run the wizard again.
Did you select all the QuickBooks lists you want
If you leave a list unselected, names on the list are not synchronized. For
example, if you select the Customers & Jobs list and Other Names list but leave the
Vendor list unselected, no vendor names will be synchronized.
Did you select the wrong Outlook folder as the
During a synchronization, QuickBooks data can be added only to one Outlook
folder—the default folder that you selected during the synchronization
setup wizard. To make a different folder the default, run the wizard again.
your synchronization settings