There are times when users will try and send an email to someone but the email may bounce back saying it was undeliverable or the user may be receiving an error when attempting to share their calendar with someone else. Clearing the autocomplete cache may help resolve these errors.
1. Inside of Outlook click the "New Email" button:
2. In the "To" field begin typing the email address or the name of the contact you would like to clear from the Autocomplete cache.
3. Click the "X" next to the name suggestion box to clear this email from your Autocomplete entry:
4. Once you have cleared the autocomplete for the contact, you will need to either manually type the email address or alternatively use the Global Address list to enter the contacts email address once more.