I did this the first year, but then Trisha Fugelstad pointed out something that made a lot of sense; if you send home permission slips and ask for the parents' email addresses, you can sign them up yourselves and ensure that they receive the email notices. This, in return, will boost your revenue and rankings. Our school is now #3 in the state. Not bad for a VERY rural school system made of a total of 2 school buildings.
More work in the beginning, but if you specify that it will cover the students for the entire time you have them in class, you will only send it out once. After that, it is a matter of catching the new kindergartners and transfer students. Worth the time in the long run, in my opinion, having done it both ways.