A legal notice is a formal written communication between the parties. Through a legal notice, the sender notifies the recipient about his intention of undertaking legal proceedings against the other party. The purpose of a legal notice is to make the receiving party aware of the grievances of the sender.
A legal notice is mostly sent by an advocate on the behalf of his or her client. It is not mandatory for a person to send a legal notice through an advocate, they can send a legal notice on their own accord without the help of an advocate.
Legal notice i.e. private notice came from the Advocate’s Office so there is no need for court seal or court clerk and it would very much be considered valid.
Since the notice reached you late, you may still appear before the high court and tell that you got the letter beyond four weeks and show the proof. The High Court may then considere and give sufficient time to you for your reply.
Usually when the notice is served an acknowledgement card or any other proof that you have received the notice will have to be given to the Court to make it exparte.
In case of no response or acknowledgement, they will have to serve a fresh notice to you.
Reference: Code of Civil Procedure, 1908