Auto complete feature is good but sometime it cause problems if you select suggestion blindly, because it can show mistyped addresses and can make you select them. In this guide i will show you how you can remove these addresses.
How to Remove addresses from Auto-Complete or Auto-Suggest
The Auto-Complete or Auto-Suggest feature of Outlook keeps a cache of addresses you’ve recently used. It is not related to the default Contacts folder, they are kept in a special cache location.
Removing a single address
When addressing an email and a name you want to remove pops-up, use your arrow keys on your keyboard to select it and press Delete Key.
In Outlook 2010 and Outlook 2013, you can also click on the X icon on the right side of the selected list item to delete it from the suggestion list.
Another method, in Outlook 2010, is to remove the contact item from the Suggested Contacts folder. To see all your Contact folders, switch to the Contacts Navigation (keyboard shortcut: CTRL+3).
Disable Auto-Complete (Auto-Suggest)
To disable this suggestion feature completely follow these steps
Outlook 2007 and Older Versions
Tools-> Options-> button E-mail Options…-> Advanced E-mail Options…-> deselect: Suggest names while completing To, Cc, and Bcc fields
Outlook 2010, 2013 and Newer Version
File-> Options-> section Mail-> Send messages (Group)-> Deselect Use Auto-Complete List to suggest names when typing in the To, CC and Bcc lines
Remove all addresses from the Auto-Complete (Auto-Suggest) list
If you want to reset the Auto-Complete (Auto-Suggest) list to remove all addresses at once, use following steps depends on your version of Outlook.
Outlook 2007 and older versions
The addresses are kept in a separate cache file with the nk2 extension. By renaming the file to .old while Outlook is closed the entire Auto-Suggest list will be reset.
This file can be found .and can be found in the following location.
Outlook 2010, 2013 or newer versions
In Outlook 2010, 2013, 2016 the Auto-Complete list is kept in a special hidden message in your mailbox. Resetting the list can be done in the following two ways;
Empty the Suggested Contacts folder. (only applies to Outlook 2010)
The contacts in the Suggested Contacts folder hold a relation to the Auto-Complete list. Delete a contact from this folder and it will also be removed from the Auto-Complete list.
Empty Auto-Complete List
Using the "Empty Auto-Complete List" button. When using this option the contacts in the Suggested Contacts folder will not be deleted.
You can find this option here:-
File-> Options-> section Mail-> option group: Send messages-> button: Empty Auto-Complete List
Startup switch: cleanautocompletecache
By starting Outlook with the cleanautocompletecache startup switch you’ll achieve Empty Auto-Complete List.
You can execute this switch in the following way (note the space in the command);
Start-> type; outlook.exe /cleanautocompletecache