To disable Outlook auto-mapping of a delegated mailbox, you must first remove full access permissions for the delegatee and then re-assign full access without enabling Outlook auto-mapping.
To disable Outlook auto-mapping on a mailbox, do the following:
- Open up user properties, select the Mailbox tab, and click Mailbox Delegation.
- Remove full access permissions from the user who should have Outlook auto-mapping disabled.
- Click OK twice to apply the settings.
- Re-open user properties, select the Mailbox tab, and click Mailbox Delegation.
- Re-assign full access permissions to the user and de-select ‘Enable Outlook auto-mapping for new delegate(s).’
- Click OK twice to apply the settings.