Yes, it’s true that your filings may get lost after they’ve been delivered to USCIS. In our experience, it’s extremely rare for USCIS to lose a package after it has been delivered to its facility. Oftentimes, it’s the carrier that may have lost/damaged the package while on route to USCIS. This may happen due to no fault of anyone such as extreme weather or a car accident. For time-sensitive filings such as cap-subject H-1Bs or responses to RFEs, we encourage clients to file ASAP, a few weeks before the deadline so that we may refile in case of misdelivery.
For RFEs, it’s important to check with USCIS 60 days after the response has been delivered. 60 days is the minimum number of days that you must wait before you may contact USCIS and inquire about RFE status. In almost all cases, USCIS will acknowledge receipt and ask you to patiently wait until the case is adjudicated. But sometimes as the example below shows, USCIS does not acknowledge receipt and you may think the whole world has just ended.
But don’t worry, there is a fix. You’ll be asked to re-submit the RFE response together with evidence that the initial response was delivered on time as well as USCIS’ correspondence regarding the missing RFE response (similar to the example below). It is therefore important to always use mail tracking and delivery confirmation and follow up on your RFE response as soon as you are eligible to do so.