If a customer place 2 or more orders, he should be able to combine it into 1.
And the admin also can have the same ability
Rob Ridley commented
If the customer places an order - pays for it - remembers something else he wanted - and places a second order.... Happens fairly often. Challenge would be to deal with combined shipping recalculation and partial refund for reduced cost of combined shipment. I like the idea, but not clear on how it would work.
Dwaipayan XTech Team commented
If a customer orders 3 different providers products he should get only one consolidated email.If any provider has received 10 or 12 orders in a day he should get only one combined email instead of 12 different email.