Add a Bcc or Reply-To header in a Mail message
09/02/2010
When composing a new message in Mail, press Command-Option-B to add a Bcc header, or Command-Option-R to add a Reply-To header to the message.
Reply to a message in Mail via iChat
08/15/2010
When reading an email message in Mail, do Message> Reply With iChat to reply to the sender via iChat (if they are currently available).
Make a new Mail message by dragging and dropping text
07/16/2010
Drag and drop selected text from any program onto the Mail icon in your Dock to instantly put that text into the body of a new email message.
Save all attachments in a Mail message at once
07/09/2010
When viewing a Mail message with multiple attachments, Option-click the Save button to save all attachments to your Downloads folder at once.
Always send Windows-friendly attachments in Mail
07/01/2010
In Mail, to make files attached to outgoing messages Windows friendly by default, do Edit > Attachments > Always Send Windows Friendly Attachments.
Convert any document to PDF and send it via Mail
06/18/2010
In any program's Print dialog box, click PDF > Mail PDF, to convert the document to a PDF and attach it to an outgoing Mail message.
Clean up your list of previous recipients in Mail
05/10/2010
In Mail, to clean up the list of all recipient's addresses to which you previously sent email, do Window> Previous Recipients.
Easily add attachments to new Mail messages from the Finder
04/11/2010
To automatically add a file or folder in the Finder as an attachment to a new, outgoing Mail message, simply drag and drop it onto the Mail icon in your Dock.
Add attachments to Mail messages via the Dock
03/05/2010
Drop any files (or folders) onto the Mail icon in your Dock to automatically add them as an attachment to a new, outgoing email message.
Easily export pics from Mail into iPhoto
02/20/2010
To export pics in a Mail message directly to into iPhoto, press and hold the Save button in the Mail message and select "Add to iPhoto" from the pop-up menu.
Resize photos inserted into Mail messages
02/05/2010
When composing a Mail message with photos, click the Image Size pop-up in the lower right corner to automatically resize them.
View images in Mail as a slideshow
01/25/2010
When viewing a Mail message containing images, Option-click the Quick Look button in the header, to view them as a slideshow.