If you have to send out the same email message frequently you can save yourself a bucket full of time by creating a template of the message so that all you have to do to send it out is enter the email address of the recipient. This tip works for Mail and it may only work in Lion. If anyone finds that it works in earlier versions please leave a comment to that effect.
In Mail, click on New Message and enter the subject, choose the from address, and create the message. Don’t include any salutation, but leave a space for one if you plan on using one.
Next, select “Save as Stationary” from the File menu.
A window will open asking you to name your new stationary. It also tells you that your new stationary (template) will be saved to the Custom section of the stationary picker.