Suggested Contacts folders holds addresses but no suggestions are being made when composing mail

Even though the Auto-Complete feature and the Suggested Contact folder in Outlook 2010 are almost serving the same purpose, they are actually 2 separate features with both their own storage.

Suggested Contacts vs Auto-Complete

The Suggested Contacts feature creates contact items in the Suggested Contacts folder when you are sending an email to someone who isn’t in your Contacts folder yet.

The Auto-Complete feature keeps a list of addresses of everyone that you emailed to, regardless if or where that contact/address is stored. This list is kept as a combination of a hidden message in your mailbox and in the RoamCache folder on disk (see below).

Resetting the Auto-Complete cache

To reset your cache, it is recommended to use the “Empty Auto-Complete List” button in the Options dialog.

File-> Options-> Mail-> section: Send messages-> button: Empty Auto-Complete List

Resetting the Auto-Complete cache is the first step to fix and refill the list.

As an alternative, you can start Outlook with the cleanautocompletecache switch.
(Note the space in the commands below)

• Windows XP
  Start-> Run; outlook.exe /cleanautocompletecache
• Windows Vista, Windows 7 and Windows 8
  Start-> Type; outlook.exe /cleanautocompletecache

In addition, you could manually clean up the RoamCache folder when Outlook is closed.

• Windows XP
  C:\Documents and Settings\%username%\Local Settings\Application Data\Microsoft\Outlook\RoadmCache
• Windows Vista, Windows 7 and Windows 8
  C:\Users\%username%\AppData\Local\Microsoft\Outlook\RoamCache

Filling the Auto-Complete cache with Contacts and Suggested Contacts

Once you’ve reset the Auto-Complete Cache, you can fill it again with contacts from your Contacts and Suggested Contacts folder in the following way;

1. Place Outlook in Offline Mode by clicking on the “Work Offline” button on the Send/Receive tab.
2. Create a new email.
3. Click on the To… button.
4. Select all the addresses from the Contacts folder
5. Click on the To-> button
6. Repeat step 4 and 5 for contacts stored in other locations which you can select by clicking on the list under Address Book.
7. Click OK.
8. Send the message.
9. Move the message from your Outbox folder back to your Draft folder.
10. Place Outlook back in Online mode by again clicking on the “Work Offline” button on the Send/Receive tab. (Note that the icon itself always holds a red cross in it)

Your Auto-Complete feature should now work again when addressing a new email.

You can quickly refill the Auto-Complete cache after a reset.

Still no suggestions after restarting Outlook?

Is your Auto-Suggest feature broken again after restarting Outlook? As the cache is being stored when Outlook closes, it is very likely that an add-in isn’t letting Outlook close gracefully.

To troubleshoot this see; AutoComplete addresses lost in Outlook 2010