For information about Mail in newer versions of OS X, see this article.
Setting up email accounts
The first time you run Mail, Mail will display the Mail Setup Assistant. If you have already set up an email account, you can manually begin the Setup Assistant by choosing Add Account… from the File menu.
The Mail Setup Assistant can automatically configure accounts that use the most popular email services, including Gmail, Yahoo!, AOL, Windows Live Mail, and Exchange 2007 servers that support AutoDiscovery. For these popular services, just enter your Full Name, Email Address, and Password and you're done.
If Mail cannot automatically configure your account, this article details the information you will need from your email service provider or internet service provider to set up Mail.
Once you have configured your email accounts, you're ready to send and receive email messages.
Composing a new message
To compose a new message, click the New Message button in the toolbar.
To address your email to someone, just start typing the recipient's email address in the "To:" field. If your recipient's email address is in Address Book or if they have sent you an email before, Mail will autocomplete the email address for you as you type. If you'd like to browse your contacts for email addresses, click the Address button in the toolbar. Mail will display your Address Book contacts, from which you can set multiple recipients easily. Corporate users can set up Mail to autocomplete and browse LDAP and ActiveDirectory contacts.
Once you've added some recipients, type a subject in the Subject field and start typing your message.
Adding attachments and photos: Mail makes it easy to include files and photos that you want to send as part of your email. To attach files and photos, just drag them into your message. To browse your files, click the Attach button in the toolbar of your new message. Mail also includes a Photo Browser that lets you easily pick photos from your iPhoto collection to add to your email. Click the Photo Browser button in the toolbar of your new message to quickly add photos from your collection. Once your photos have been added to your email message, you can set their size by using the "Image Size" popup menu at the bottom of your email message.
Stationery: Stationery lets you send beautifully styled emails that include your own photos. Click Show Stationery from the toolbar of your new message and select from a number of Apple-created designs.
Messages sent to you arrive in your inbox. Mail informs you that a new message has arrived by displaying a red badge on the Mail icon in the Dock, and can also play an alert sound. Once in Mail, click your Inbox, then click on the new message to view it. To reply to a message, click the Reply button on the Mail toolbar.
Viewing attachments with Quick Look: Quick Look makes it easy to instantly preview attachments that you receive in your Mail including Microsoft Office documents, PDF documents, and photos. Just click the Quick Look button in any email message that includes a supported attachment. If you're viewing photos, you can use Quick Look to view them in a slide show, one by one, or as a grid of tiled previews. You can even add them to iPhoto, all directly from Quick Look.
Searching Mail: Rather than scrolling through your email to find the message you are looking for, type the details you remember about the message into the upper-right Search field. Mail's Spotlight-powered search will try to find your message. You can refine your search to cover the content of an entire message, sender, recipient, or the subject line of your emails.
Filtering Junk Mail: Mail automatically detects junk mail messages (also called "spam") and visually identifies them by displaying them in brown text in your inbox. If Mail mistakenly marks something as "junk", you can click the Not Junk button to help train Mail. If a message isn't marked as "junk" but should be, click the Junk button to help train Mail to better identify junk messages.
Smart Mailboxes: Just as you can create a Smart Playlist in iTunes, you can create a Smart Mailbox in Mail that automatically updates its contents to match criteria that you set. For example, you can use it to keep all messages that are seven days old about a specific project, making it very easy to see that set of emails.
To create a Smart Mailbox: Choose New Smart Mailbox… from the Mailbox menu. The Smart Mailbox sheet will drop down and allow you to set the criteria you want to have for your messages to appear in the Smart Mailbox, click OK when you have it configured to your liking.
Notes: Ever email yourself a reminder that gets lost in your inbox? Mail lets you write handy notes you can access from anywhere, they can even sync with your iPhone notes. Use Mail Notes when you brainstorm ideas, jot down meeting notes, scribble a phone number--notes can include graphics, colored text, and attachments. Group notes into folders or create Smart Mailboxes that group them for you. Since your Notes folder acts like an email mailbox, you can retrieve notes from any Mac or PC using an IMAP mail service.
To Do Items: Forget manually adding a new item to your To Do list every time an email hits your inbox. Use To Dos by simply highlighting text in an email, then clicking the To Do button to create a To Do from a message. Include a due date, set an alarm, or assign priorities. Every To Do includes a link to the original email or note, and To Do automatically appear in iCal, complete with any changes you make. And since To Dos are stored with your email (when using an IMAP mail service), you can access them from Mail on any Mac.
Tip: Want to learn more about Mail? Check out the built-in Mail Help guide on your Mac (in Mail, choose Mail Help from the Help menu).
Note: If you can receive emails yet you cannot send email, contact your Internet Service Provider (ISP) and ask if they block SMTP to external email services. If they do, see if you can be exempted from this policy and have the block lifted. ISP often have their own email service contained on their own network. It is important to ask if the ISP is blocking SMTP traffic that leaves the ISP network for a email server that is on another network. See also: Troubleshooting sending and receiving email.