The recent update has a setting where you can set receipts to be emailed automatically to a customer whenever they put something onto their account if the customer has an email address in their account. To activate, please tick the new option in customer maintenance.
You can also set it in System Setup Values>Account, to automatically set all new customers made via the register to have receipts emailed to those customers' email address.
It will save a lot of time as rather than printing, the receipts are now electronically sent directly without the need to print anything.