I received the same letter in the mail today and I am in Canada.  Found it funny since I have received many emails like this in the past but never in the mail.  The weird part is that I am just recently married and they had my married name and we just moved a month ago and they had my new address already.  Scary.  Sent an email in response to the one listed on the site not on the letter just to see what they ask for.  Should be interesting to see what they say back.