Turning Off Contact Info from Mail (OS X El Capitan)
With Apple OS X El Capitan (10.11), Apple introduced a feature that picks out email addresses from the Mail application and populates it within Contacts. It is meant to serve as a nice assistant when drafting emails however it is perhaps a little too eager.
When using the Mail application at the University, this feature will pull information from the signature line of mailing lists that generally have the name of the list as part of it. Mail will pull that address and associate it with the sender regardless of whether they are a list administrator–a mere post to the list can trigger it.
In order to disable this feature, you must go into the Contacts application and open the application’s Preferences window (Contacts > Preferences or Command-,), then uncheck the box to Show contacts found in Mail (seen below):
Once that box is unchecked, you will see a prompt asking if you really want to do this. Click Turn Off to proceed:
Links to Additional Content
UO mailing lists are the main interference of this software feature. If you are a list administrator, click here to read about how to remove the list address from the signature line.