How To Write A Letter Through Mail . Browse through the files on your computer to find your cover letter and click to attach it to the email. Choose between block or indented form. Student Mail and Package Receipt College from www.ggc.edu It is extremely necessary to know how to write a formal email when you begin your professional career. First, as the sender, type your full name and address aligned to the left side, just as you would when addressing an envelope. Instead of entering an email address in the recipient.