How difficult or easy is to file a class action suit against the immigration department?

No. 'In general,' after 1996, applicants or aliens purportedly cannot file a class action lawsuit against the INS (now USCIS) as a matter of law. There may be exceptions based upon the Administrative Practices Act, where the DHS is alleged to be wilful and wanton or utterly reckless en masse. However, you can complain to your U.S. Congressman and Senator.

Such class action lawsuits may be tolerated by the USCIS until administrative remedies are achieved and a settlement is reached. This happened in the Ramos Case in Chicago. However, class action lawsuits against the USCIS are both rare and arguably risky for dismissal. Yet, some are still filed by accomplished immigration attorneys attorneys and are successful.

If an immigration attorney helped with the process, then two sets of receipts would have been sent; one to the attorney and the other to the applicants. This makes it less likely that the notices would not be delivered. It is also easier to argue that USCIS did not send the notices, where both the attorney and applicants do not received the documents.

This unfortunate USCIS loophole on USPS non-delivery is awkward. If the USPS is negligent, then you cannot successfully sue it as a matter of law. Government Agencies can be negligent. A person must allege and prove that USPS is wilful and wanton or utterly reckless. This standard can be difficult to prove. The USCIS knows that it is cheaper for an applicant to file, again. To learn about what those legal terms actually mean can require an attorney.

The above is general information and does not create an attorney client relationship.