This article will explain how to disable Suggested Contacts in Outlook 2010.

1.  With Outlook open, Click File > Options > Contacts

2.  Uncheck “Automatically create Outlook contacts for recipients that do not belong to an Outlook Address Book”  Once this option is disabled no more contacts will be added to the Suggested Contacts folder, but the existing Suggested Contacts remain.

Remove Suggested Contacts Folder:

1.  With Outlook open, click Contacts (Located in the bottom right below Mail and Calendar) Right-click the Suggested Contacts Folder > Properties > Outlook Address Book

2.  Uncheck the “Show this folder as an Email Address Book” option and click OK.  This will remove the Suggested Contacts folder as a Contacts Folder.