How do I clear auto-complete addresses in Outlook?

If there are issues with sending to an existing email address, clearing the cached email address may resolve the issue.

To clear the cached address:

• Open a new email.
• Begin typing the email address and when Outlook auto-completes the address, click on the 'x' to delete the address.
• Retype the email address in full.
• Send the email.

Alternatively, to clear all auto-completing addresses:  

• Select the "File" menu, and select "Options".
• Select "Mail".
• Scroll down to the "Send Messages" section, and click "Empty Auto-Complete List".

If you still have issues sending to the existing email address - in particular a known email address within your organisation - please update your Offline Address Book.