"Make this my card" adds the icon "Me" against a selected Contacts name. This pegs the name as the sender of emails from a particular person's computer. I have several Apple devices on my in-house wifi, all having "Contacts" on iCloud. When I select a card, for example on my MacBook Pro, and set my name in "Contacts" to "Make this my card" all my emails, from multiple shared addresses, are sent from my name. Great! Unfortunately, iCloud changes every other devices' "Make this my card" selection to my name as well! This causes emails originated on other devices to be sent in my name! Help.