Forwarded Certified Mail
If the USPS has updated the tracking information for one of your letters with a status update that says "Forwarded", that usually means that the recipient has set up forwarding for their mail to redirect it to a different, more preferred address.
If your letter was going to a business and not an individual, often times organizations will set up forwarding so that all of their incoming mail goes to the same place, making it easier for them to process.
Forwarding mail is a fairly common occurrence for certified mail. If you have any questions regarding your letter we recommend first entering the tracking number at www.USPS.com to see if their website provides and additional information regarding the letter.