You will receive a copy of a letter in the mail that you received online -- but it will probably take longer than a month to receive a reply to a specific letter. I tend to send a letter every 3 weeks to a month, replying to whatever letter I most recently received (if I had one). In future letters I'll see comments that let me know they did see my letter -- but not necessarily the next letter I receive.
Jessica, I’m so sorry for any confusion or concern, and I’m happy to help you. Regrettably, I was unable to locate your account using your email address. Will you please provide either your sponsor number, child’s ID number, or the email address associated with your account? If you don’t feel comfortable providing your information publicly on this forum, you are also welcome to email firstname.lastname@example.org.