assuming this thread is about Thunderbird, moving over there from Firefox support

Open the Address Book window. Do you have a Directory Pane showing down the left margin with your books listed? If not from the Menu Bar select View-Layout-Directory Pane.

From the Directory Pane you can select the folder for any of your books.

To add a contact press the New Contact button and fill out the form.

If you want to add a contact from an email that you received you need to work from the header of the Message Pane or a message opened in a Tab. When you view the header of a received message there will be a star to the right of the senders address. If the star is filled with color the contact is already in one of your books. Clicking on an unfilled star will add it to the Personal Address book Clicking on a color filled star will open the contact edit dialog box where you can add details to the contact or change the book it is saved in. This is NOT the same star to the left of the message subject line in the Inbox.

The two default address books are the Personal and the Collected books. The Personal book is for contacts that you add and most use this as the main book. The Collected book collects addresses of people that you send mail to.

You can move contacts from one book to another by drag and dropping the contact.

There is something called the Contact Sidebar that is in the Write window. If yours is not showing when you open a Write window press F9 to toggle it on. From the Contact Sidebar you can add contacts to your email. You can double click a contact to add them to an address field. You can drag and drop a contact to an address field. If you are adding more than one contact to an email you hold the control key down while clicking all the contacts you want and then use one of the Add To: buttons at the bottom of the sidebar.

You can also start typing a contact into one of the address fields and Thunderbird will offer suggestions from your address books. This method has been a little buggy in the latest versions so watch this one closely to be sure you get the contact you thought you picked.

MamieL said

The Address Book is completely useless to me if I can't add Contacts to it. There is currently no way to do this and no place to go for instructions. Can someone please post understandable instructions about how to find and then open my Personal Address Book or the Collected Address Book and then please tell me what the difference is between them? It is VERY non-intuitive.

Thank you for your answer. I understand most of it and now have figured out how to access my Personal and Contact Address Books at least. I will work on learning how to move addresses from one to the other next.