Outlook name cache not updating
While it was a much requested featured over the years, Suggested Contacts was not popular and was removed from Outlook 2013.
Suggested Contacts solves both problems easily: by using a separate Contacts folder, the "good contacts" folder is not polluted with useless contacts and you don't need to remember to create contacts or worry about losing the auto-complete list.
So even though you have changed a contact's email address several times in the course of the year, the one Outlook suggests when you start typing the person's name in the To field will be the wrong one.
These phantom e-mail addresses can cause an email to bounce back especially if you had mistyped the email address the first time. Type the first three character of the cached name into the To field to trigger the Auto Complete feature. Press the Down Arrow key on your keyboard to highlight the name or email address you wanted to delete.
Users with Exchange mailboxes should switch to online mode before deleting the roamcache folder then re-enable cached mode after starting Outlook.
This ensures the cache is cleared from the mailbox as well as the local ost.
November 2017: there is a bug in Outlook 2016's autocomplete that results in Contact Groups not listed in autocomplete.
For more information, see Contact Groups aren’t listed in autocomplete We get questions like this after users upgrade Outlook: I upgraded Outlook.
Addresses are added to the hidden cache file as you send new messages and replies.If you prefer using a command line, switch, it's Clean Auto Complete Cache.To use, close Outlook and in the Start menu, Search field or Run command (Windows key R to open) type or paste the following line and press Enter to run Clearing the auto-complete list only removes the addresses you see as you type in the To, CC, or BCC fields.Furthermore, there is no way to edit the file where these names are stored since it isn't written in plain text. Nevertheless, you can delete entries from the cache one at a time when necessary.