the Knesset yesterday passed a law proposal from MKs Nachman Shai (Hamachane Hatzioni)  and Uri Maklev (UTJ) in its third and final reading (by a vote of 19-0) that would require anybody sending a piece of registered mail to provide identifying information (name and address) of the sender. The post office will not accept registered mail that does not include this information. As well, the post office will include in the note to the recipient the information of the sender.

The purpose of this is obvious - so the recipient can decide how urgent, if at all, it is for him or her to run to the post office and wait in line for the piece of mail.

The law exempts government offices, the police, fire and rescue services, courts and batei din from this law and would allow them to continue sending registered mail without the identifying information - and just state the sender as "the State of Israel". I guess the idea here is that people might prefer to not go pick up the mail if they suspect it might be a bill from the fire services or a fine from the police or a court order or whatnot.
source: Knesset