Those IOE forms mean that your case is being processed digitally, which is usually good news because those cases tend to flow through the system a bit faster. You don't have to wait for them to move your file around.
Online: Use the case status online tool to check for updates about your immigration case. You will need your 13-character receipt number from your application or petition. By phone: If you are calling from the U.S., contact the USCIS Contact Center at 1-800-375-5283 or TTY 1-800-767-1833.
You may send your forms through USPS, FedEx, DHL, or UPS. We encourage you to save a copy of your payment, along with any tracking number provided by the courier, for your records and so you can verify the status of its delivery.
Follow these simple steps to check your case status with your USCIS receipt number: Visit the USCIS Case Status Page. Go to the Check Your Case Status page on USCIS. Enter your USCIS receipt number. Type the 13-character receipt number into the provided box (without dashes). Review Your Case Status.
The first three letters of your receipt number will tell you the exact service center that takes care of your application. Other than that, you can simply check out the list of application/petition types and the offices that process them, as well as which centers have jurisdiction over your state.
The receipt number is a unique 13-character identifier that USCIS provides for each application or petition it receives. The agency uses it to identify and track its cases. The receipt number consists of three letters-for example, EAC, WAC, LIN, SRC, NBC, MSC or IOE-and 10 numbers.
Generally, I don't want people corresponding with USCIS, unless they've been asked to do so. It's generally not a good idea to just out of the blue, write USCIS a letter. So our advice generally is to not send USCIS a letter.
Your letter should be addressed to the USCIS office that is responsible for your case. You can find the address on the USCIS website or by contacting the USCIS national customer service center. You should also include a clear and professional salutation, such as “Dear USCIS Officer” or “To Whom It May Concern.”