The content of a cover letter is not the only thing you should be concerned with when you're applying for a job. On top of what you say, the actual formatting of the cover letter can make or break the entire presentation. You may think it's only an aesthetic thing, but attractive formatting shows that you took extra care and pay attention to detail. If you have to use two addresses on the cover letter, it's often because you have a different address during different parts of the year. Like all other formatting, this should be included in the most attractive way possible, which can mean including it at the bottom of the letter.
Proper formatting key to effective presentation
Format the top of your letter according to standard letter formatting, starting with the date at the top. Then skip a line and type the recipient's name, followed by the recipient's address on the next line, then the email address, and, finally the phone number, with all lines justified either to the left or right. If you're sending the letter to multiple people, change the recipient's contact information so that each letter you send uses that person's individual contact information.
Compose the rest of your letter, with your signature and name typed near the bottom of the letter and justified to the left of the page.
Skip a line and type your phone number.
Skip a line and then type "Current Address," "Summer Address," or specify a date range that you'll be at your current address, such as "Current Address 6/15/13 through 8/15/2103." On the next line, type the current street address, followed by your city and state on the next line, and then your ZIP code on the following line.
Skip a line and type "Permanent Address" or a date range during which you'll be at the second address. Then type the address details in the same way you formatted the first address.
If you are sending the letter to multiple people, type "cc:" when you get to the very bottom of the letter, and then type the name of the other recipient or recipients.