How to add or remove an email address from your Facebook account: Here’s a step-by-step guide

Managing email addresses on Facebook is essential for account security and usability. Users can add, remove, or change their ...
Ars Technica

Removing contact's email from outlook?

Basically once you send an email to someone in Outlook, their name is auto-added to the contacts list. A manager here once sent an email to a contact's personal email address instead of their ...