You can collect E-Mail addresses by adding the addresses to an address book. The following options exist:
Automatically collect new E-Mail addresses when sending or reading E-Mails by activating this function in the E-Mail settings.
Manually adding E-Mail addresses to an address book
How to manually add an E-Mail address to an address book:
Select an E-Mail.
Click on the sender's or a recipient's name in the detail view.
Click on in the popup.
Also see:
Parent topic: Organizing E-Mails