It says '0 customers', how can that be?
The process may not have started, if no DS is available for transactional (or general system) use.i select 40 customer but it displayed 0
Do you have any DS set to 'all' or 'transactional'? Only then a DS is 'available' for your 'mass email' to customers. You will see it when it works in the DS logs.i'm sorry but i don't understand