Assuming that my boss is on leave. until sunday. i would need '4 weeks notice to resign' i would need to start my new job on the 29th/30th November.

1. If i email by boss and note that I would want to resign on the 28th October, is it valid?(and meet him personally on the 31st October) or does only face to face meeting and handing of resignation only valid if its an actual physical letter

2. If i notify him on the 31st October, does it still count as 4 weeks notice if my last day or service is on 28th November?