I don't think your proposed procedure would meet with the standard financial regulations and email decisions are not valid. If not already in your financial regulations, I'd suggest delegated authority to the Clerk to set up payments in between meetings to cover those situations where an urgent payment is required (for example where the supplier won't supply the goods unless payment is within a specified timescale or where urgent action is required on health and safety grounds or to maintain essential services). This should then be report to full council in the usual way at the next available meeting. There can be an informal check that no one has any issues with proposed payments between meetings but the formal authorisation would need to be done at full council, even if it's after the payment has actually been made in accordance with the delegation.