| Introducing the Compose Page | Addressing Your Message | Writing Your Message | Personalizing Your Message | Attaching Files | Sending Your Message |
Just as you address a letter that you send through the post office, you address an email message so that Yahoo! Mail knows where to send it. An email address looks something like this:
name@yahoo.com
It includes a contact’s email name, followed by the at sign (@) and the contact’s email domain.
The To box must contain at least one address. You can address your messages to more than one person in the To box and send copies of your message to other contacts by typing their addresses in the Cc (carbon copy) box. Everyone who receives your message can see the addresses in the To and Cc boxes. To send a copy of your message to someone without revealing that person’s email address to the other recipients, use the Bcc (blind carbon copy) box.
You can also choose the return email address your recipients see when they read your message by selecting one of your email addresses in the From box.
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Open the Compose page. (Remind me how.)
In the From box, keep the return address automatically filled in by Yahoo! Mail, or select a return address from the pull-down list.
Tip: The From box only appears if you’ve set up your Mail account to send email using a different email address
, or created one or more disposable email addresses (a Yahoo! Mail Plus feature). 

In the To box, type one or more email addresses, separating multiple addresses with a comma or semicolon. (A space between addresses is optional.)

Tips:
If you want to hide email addresses so that none of the recipients can see who you’ve sent the message to, use the Bcc (blind carbon copy) box as described in step 5. To send the message, you do have to include at least one address in the To box, so use one there that you don’t mind showing to all recipients.
Do you want to use a distribution list? In Yahoo! Mail, a distribution list is part of the category functionality found in your Address Book. If you’ve created a category, type its name in an address box to send the email to everyone in the category. 
If you want to send a copy to other contacts, enter one or more addresses in the Cc box.
You might do this when there are people who should receive the message as a courtesy, but they aren’t the primary recipients.
If you want to send a blind carbon copy to contacts (other recipients won’t see these addresses), click the Show Bcc link to display the Bcc box, then enter one or more addresses in the box.

Tip: Addresses listed in the Bcc box don’t receive reply messages that are sent to all recipients.
If your Yahoo! Address Book contains email addresses, you can also use one of these approaches to add addresses to the recipient boxes:
Use a distribution list in any of the address boxes, not including the From box. In Yahoo! Mail, a distribution list is called a category. A category contains multiple email addresses and allows you to send one message to many people without having to type all of the email addresses. Unlike distribution lists, categories are also a way to organize the contacts in your Address Book. 
Choose contacts from your Address Book by doing the following:
Click the To, Cc, or Bcc link.

The Address Book window opens.
In the Address Book window, check the To, Cc, or Bcc boxes next to the contacts you want to include. These boxes are disabled if the contact information doesn’t include an email address.

Tips: If the Address Book contains many contacts, you’ll see alphabetical groupings at the top of the window with the first alphabetical group displayed. You can select contacts from one group, display another alphabetical group, and select more contacts. All of the contacts remain selected even when you view another group.

If you want to add a category to your address list, click the Categories link, then select one or more categories from the list.
Click the Insert Checked Contacts button.

Yahoo! Mail adds the email addresses that you selected to the recipient boxes in the Compose page.
Tip: You don’t need to display the Bcc box before you insert addresses from your Yahoo! Address Book. Simply checking the boxes in the Contacts window causes the box and the selected addresses to display on the Compose page.
Use the Address AutoComplete feature.
Begin typing a contact’s name, nickname, or email address in any of the recipient boxes.
The Address AutoComplete feature displays a list of email addresses from your Yahoo! Address Book that match what you’ve typed so far. Select the address you want from the list or continue typing to enter a new address.

Note: Address AutoComplete doesn’t work in all browsers. For more information, see the Address Book Help in the Help Topics listed below.
The Contacts tab (to the right of the Mail tab) connects you to your Yahoo! Address Book, where you can click a contact’s email address to open the Compose page and automatically display the contact’s address in the To box.

You can also check the box next to one or more contact names, and then click the Send Mail button to open the Compose page and display all of the selected contact email addresses in the To box.

To create categories, see the Creating Groups of Contacts (Categories) tutorial.
To use categories, see the Working With Categories tutorial.