Postdating an email
(a) A bank may charge against the account of a customer an item that is properly payable from that account even though the charge creates an overdraft.
An item is properly payable if it is authorized by the customer and is in accordance with any agreement between the customer and bank.
(2) A cheque is not invalid by reason only that- (a) it is not dated; (b) it is antedated or post-dated; or (c) the date it bears is a Sunday.
(3) For the purpose of determining whether a post-dated instrument is a cheque, the fact that the instrument is post-dated shall be disregarded.
In the UK the legislation is clear; 'A cheque is a bill of exchange drawn on a banker payable on demand'.
In the United Kingdom, post-dating a cheque carries no legal weight and so such a cheque can be cashed before the due date.
In the United States, national banks are permitted to pay checks even though payment occurs prior to the date of the check.
The notice is effective for the period stated in Section 4-403(b) for stop-payment orders, and must be received at such time and in such manner as to afford the bank a reasonable opportunity to act on it before the bank takes any action with respect to the check described in Section 4-303.