While our Mozilla Mail tutorial focuses on Windows, keep in mind that Mozilla Mail is a "cross-platform" email client: it runs and operates the same way on Windows, Apple's Mac OS X and Linux.
The Mozilla Foundation also offers the standalone Thunderbird email client: see the Mozilla Thunderbird Tutorial
The Address Book in Mozilla Mail or SeaMonkey Mail
Mozilla Mail's Address Book is used to store all your correspondents' contact information.
Aside from email addresses, Mozilla Mail lets you store physical address, website, phone/fax/mobile/pager numbers, 4 custom fields and notes. Mozilla Mail will add to the address book email addresses from people to whom you respond, a very handy feature.
To open or show Mozilla Mail's address book, go to Window > Address Book.
Ctrl+5 Show Address Book
Ctrl+2 Show Mozilla Mail
(You need to use character 2 and 5, on the left side of your keyboard, not the numerical keypad)
To add a contact in Mozilla Mail's address book, go to File > New > Address Book Card, or click the New Card button on the address book's main toolbar. This will pop open a blank address card, where aside from expected fields like phone/fax numbers, email and physical addresses, you can add custom fields.
Multiple Address Book Support
Mozilla Mail supports multiple address books, which lets you to efficiently manage your contacts. Two address books come by default, the "Personal Address Book", and the "Collected Addresses", (where Mozilla Mail adds email addresses from people you respond to.)
To create a new address book, go to File > New > Address Book in the Address Book window.
Mozilla Mail will let you use any combination of words and characters for your new address books.
Mozilla Mail will not prevent you from using a name already taken for your new address book.
Email Distribution List
Mozilla Mail also lets you create "Lists", that are collections of email addresses. "Sales Team" would be an example of list, and would contain the email addresses of all the employees who work in the sales department. To create a new email distribution list, go to File > New > Mailing List, or click the New List button.
Each email contact can be individually added. You can also add email addresses pre-existing in other address book; however, this will not carry over the rest of the information.
To share a contact between several address books and distribution lists, create the list without him/her. Then drag the contact from a pre-existing address book to the new address book or distribution list.
Likewise, updating a contact in one address book or email distribution list will not update the other instances of that contact: Mozilla Mail's address book is not a database, merely a receptacle for static information.
To quickly add email addresses in a mailing list, hit enter after each email address to go to the next.
Address Cards in Mozilla Mail
Aside from displaying static text information about a given contact, Mozilla Mail transforms URLs and email addresses into clickable links. It also shows a Get Map button that opens a browser window to Google Maps for the physical address.

By default, Mozilla Mail will add to your Personal Address Book email addresses from people to whose emails you respond.
Finding Contacts in Mozilla Mail
Mozilla Mail's address book contains an advanced search utility, which lets you specify very narrow filter to find information. This interface is well designed, and intuitive, so we'll simply mention its existence. (Tools > Search Addresses.)


Email Clients Tutorials
Mozilla Mail Tutorial