How To Clear Autocomplete in Cache in Outlook

Microsoft Outlook caches a list of email addresses/nicknames that you’ve had previous correspondence with, allowing Outlook to autocomplete new email messages with the cached entries. Issues can occur resulting in failed deliveries if a cached email was spelled incorrectly or the mailbox no longer exists.

To clear the cache in Outlook follow these simple instructions depending on your version of Outlook:

Outlook 2010 and later versions

1. Compose a new email message.
2. Start typing the nickname/email address that you want to remove from the cache.
3. When the entry appears in the list, move your mouse over the name until it becomes highlighted. Do not click the name.
4. Click the ‘X’ that appears next to the highlighted name.

Outlook 2007 or Outlook 2003

1. Compose a new email message.
2. Start typing the nickname/email address that you want to remove from the cache.
3. When the entry appears in the list of suggested names, use the ‘UP’ and ‘DOWN’ arrow keys on your keyboard to select the entry, and then press ‘DELETE’ on your keyboard.

To clear ALL of the cached entries in Outlook, follow this article provided by Microsoft:
(Applies to: Outlook for Microsoft 365, Outlook 2021, Outlook 2019, Outlook 2016, Outlook 2013, Outlook 2010)  How To Clear Autocomplete Cache in Outlook

Useful Links:

• Why are emails to new email addresses I just set-up still bouncing?
• The Email Bounced Back to the Sender
• The Email Didn’t Bounce Back to Sender, but it hasn’t Arrived
• How to Flush your Local DNS Resolvers Cache